It's your choice, but note that you are welcome to remain as a mod either way, even with just your Lemmy.World account. As you say on a casual basis, you just won't get access to the reports that would help alert you to trouble spots identified already by people browsing the community. We now have 3 other mods all with Discuss.Online accounts so we're good, but could always use you chipping in when we haven't yet, again if you still wanted.
Matrix is a whole separate thing - it's like Discord. It too, like Lemmy, is entirely Free & Open Source Software, and the accounts and usage and everything is also free. It offers a "group"/channel style of communication rather than Lemmy's basis of topical "threads", which we all love but for the purpose of discussing mod activities the group method really is better. I just got it yesterday, and immediately I was able to access it both from a webpage and I downloaded an Android app (Element) as well. I like it! If you want, you could create a Matrix account, and optionally tie it into your Lemmy one by adding it to your Settings -> Matrix user, which adds a new button to Send Secure Message to your account Profile I believe. I don't see that button for myself for whatever reason, but supposedly Matrix and Lemmy go together very well.
In any case, nobody is asking you to give up your Lemmy.World account - I agree that would be far too much hassle! ๐ Let us know what you want to do here? Casual mod + talk with us on Matrix, just the former, or nothing anymore?
Oh I hear you. Back on Reddit, I was not liking the idea of joining a place made for and run by supporters of Russa, China, and North Korea (I mean, software is just code, but still...), so I was ALL ABOUT Kbin!:-) Ernst let himself down - and with good reason, due to his job and his family and his overall life - and thereby all of us, by not sharing his instance admin duties with anyone else who could take over. Especially when he announced that he was going to the hospital (and then did not respond to anyone for weeks afterwards), THAT is when the spam started, I noticed, from communities where the mods had abandonded them. The big waves did not happen until later, but I noticed earlier waves even then. That much at least might not the fault of Ernst, but it became his duty at that point to shut those communities down, and yet he refused (or was unable to, either way), and so the spammers had a field day with his negligence. (Also, to be honest, the mods abandoning it really was his fault as well - I myself could not log into the server for multiple WEEKS at a time, and when we did get in it was so slow as to be practically even if not wholly non-functional. Mods only abandoned an already sinking ship at that point. And yes it did rally back a bit, and then sunk again, repeating a few more times before it finally went down and just never came back up again.)
It actually serves as quite the lesson for us all. Too bad it is at Ernst's feet, but it is what it is - the guy was somewhat heroic I thought, for taking on the project of starting up an entire alternative codebase to Lemmy, and Mbin today is somewhat fantastic still! And yet... he was not perfect, nobody is:-|.
I am aware of quite a few examples of defederation - just go to any instance and search for that word and you'll see many:-). But I've never seen one that did not cite a very specific reason, that without researching further I thought at least naively sounded reasonable to me. Also I've actually caused an example of defederation: see my Petition to defederate from hexbear.net, which also offers several links to other petitions from instances that did the same quite awhile ago. Here's an interesting one from Beehaw to Lemmy.World and sh.itjust.works: https://beehaw.org/post/567170 (and then their response in return: https://sh.itjust.works/post/129725).
But yeah, Mastodon has been going stronger than Lemmy for longer iirc, and I've heard that it it plagued by defederations, so I definitely need to preemptively agree with you that defederations for no reason are bad. It might be like talking about divorce: always bad, yet other things are worse sometimes, so sometimes the least worst choice, while other times perhaps done too readily, and either way a very very serious issue that should be given the most serious of thought. I'm with you there.
I also agree that Kbin.social was not right-wing: on the other hand I can kinda understand that one better, having heard similar thoughts before. The USA as a whole is more right-oriented than e.g. the EU that is more left-oriented, so e.g. for myself inside the USA, Bernie Sanders seems quite the leftist compared to every other politician I've even heard of here, and yet compared to those in the EU he would be considered centrist or even right-wing. i.e., much like introvert vs. extrovert, the standard of comparison is relative to where someone is located at, currently.
Even so, why should one instance defederate from another instance purely due to personal preferences like that? (precisely as you said) Reasons to defederate that are fully valid, imho, are when one side is not engaging in good faith argumentation. Which I don't recall ever happening on Kbin.social. Therefore, the side defederating from it was likely to have been engaging not in good faith? So perhaps good for you to have gotten away from it then? (Though to be clear: conversely, the fact that Kbin.social later was sending out spam all across the fediverse is a perfect reason to defederate from it.)
The UX of the Fediverse is really quite poor, which is part of why so many are flocking to the likes of BlueSky even as they leave Reddit + X + Facebook, rather than Lemmy/Mbin/PieFed(/Sublinks?) + Mastodon + Friendica. A major part of the reason where Lemmy at least is concerned is the lack of cross-instance moderation ability, which severely hinders people who are not all lumped together onto one single giant instance (one Lemmy dev, Nutomic, put this onto the roadmap, but not until software version ~0.20, whereas the most recent version is currently only 0.19.7, so this won't be for perhaps another half to full year before that eventually gets added? especially considering delay also from after the sourcecode is released until it is installed, e.g. Lemmy.World that has literally ~80% of all Lemmings on it is still on 0.19.3, and they were outright EAGERLY awaiting 0.19.6)
A bit of a tangent: I wonder if the more Threaded conversation style, where you follow "topics" rather than "users", gives Lemmy the edge in terms of UX? Like, even if you cannot follow one person - although defederations seem more rare here in the first place - you will still get access to so much great content of a similar theme.
About your tangent regarding politics: I hear you, and I sympathize. If it helps, remember that (1) America is going through a REALLY rought time right now, like repeal of the 50-year-old protection to have abortions is literally a matter of life or death for a good half the population, and also (2) we are vulnerable to disinformation campaigns being waged against us from foreign powers as well as internally, and people are just like sheep, wanting to be lead, so the problem comes when someone arises who offers to do that but has a nefarious motive:-(. And yes, there are very many internet trolls who lack nuance entirely or in part - with those you cannot converse, you are right about that, and THOSE are good targets for defederation imho, not b/c of "politics" but b/c of "trolling", the former being a mere difference of opinion but the latter being the most important criteria there is on the internet: lack of good faith in discussions. :-)