I also feel this anxiety in other parts of my life too.
I try to reply to everyone and I'm afraid it makes me come off as intense or competitive (like I need to get in the last word) when I'm really just trying to say I heard and read what you said. Or I try to make it clear I'm not upset with something or ignoring them on purpose.
My parents didn't pay much attention to me growing up, and I think that's something that affects the way I interact with people. I don't want people to feel like I'm ignoring them or that I don't care, so I try to reply when I can.
On the other hand, that's overwhelming, and honestly untenable. Otherwise, I would reply to my texts, emails, etc.
I don't think many people are built for all the ways we communicate these days.
What an utterly predictable person.