No Stupid Questions

The two aren't correlated in that way because nobody is thinking to themselves "I want to inflict an amount of damage commensurate with what can be treated by modern medicine". If things have devolved to violence, the goal is probably to kill the other.

Politics gets more dangerous as tensions rise in a country. It has nothing to do with what injuries people think can be recovered from. Also we as a society have mostly decided that violence isn't a good way of solving political disputes. A duel doesn't tell you who is right, only who is left.

And let's not forget, duelling always carries a risk of death. Nobody is thinking in terms of "oh don't worry, as long as they get me to a hospital quick enough I'll be fine", because a bullet to the heart or head is still a killing blow.

Pain hurts and people avoid that

way more survivable than it was 100 years ago

Threat assessment, in a nutshell. Back then you could be relatively sure you were evaluating the threat level of any encounter fairly accurately. You could tell if your target was far more privileged than you, deadly weapons were reasonably obvious. These days you have no way of knowing whether your target has immediate access to deadly weaponry, an unseen group of potential reinforcements via socials, or if law enforcement will be able to investigate and prosecute your actions whether there are witnesses or not.

Clarifying edit: I answered in the spirit of speculation, allowing the premise for the sake of conversation.

I think it stems more from the correlation between modern medicine and modern weaponry.

A duel would be difficult with swords, and yes you could be cut badly but more bruised and possibly broken bone.

A duel with guns, yeah you dead.

You aren't accounting for the increase in cool stuff that makes people want to stick around longer. There's at least one more Dune movie coming and even a Rebel Moon for the Snyder people. When dueling was popular people were going to church for fun... If you believe in an afterlife and most of your time is spent peasanting about, why not have some fun in a duel?

Even if people were thinking “i want to just harm someone in a way that they can still make a full recovery”, modern medicine also tells us much more about ptsd and other mental health issues that can happen from violence. So even if the while premise of “let’s get violent, they can heal” was true, it would still lead to less violence

Give it about 300 more years....

I wager the reason why people are not dueling each other, to solve their differences today, is that they simply have more options in how they go about it. I don't think the survival rate of stab wounds factor in to the decision at all. We have a more accommodating legal system to turn to. One that serves more people than ever.

On another note. If you have to pay for your own medical cost and you live in a place like the USA; then you would probably want to die. If you live in a more civilised pace, then your fellow citizens will pay for your treatment and then promptly lock you up for wasting taxpayer money and endangering yourself and others, like a crazy person.