On the topic of "why don't you just ban all the trolls?" A few reasons.
1) We have a warning/ban system that works and is more consistent than the judgment of several moderators, so we are going to use it. It accomplishes the same thing. It bans people after several warnings, and it bans them for longer and longer periods of time as they get more warnings.
2) We are careful to not ban people who are just annoying, either to us or to the people reading the forum. If we do that we run the risk of the forum turning into one big homogenous opinion, since anyone with (strongly) differing opinions get removed.
3) For people who are annoying, we now have the "hide" feature, which is provided for exactly that reason. So if someone annoys you, just hide them and don't read their posts. (And really hide them, and don't regularly post "oh I see PutinLover is back, but all I can see is 'you have hidden this content' because I have hidden them and thus never even notice them any more, or whatever they are posting!")
4) Underlying all this is the question "what is trolling?" We have a handy definition in the rules - it's "posting inflammatory material specifically to provoke a negative response from someone." But what is that exactly? Is a troll someone who posts 50 times a year on the "sacrifices to the second amendment" thread, constantly complaining about basically the same thing in order to annoy conservatives? (innocent lives lost via gun violence) 100 times a year? How about someone who constantly posts "I hate Biden" or "I hate Trump" to annoy others? Or who always denies climate change is happening, or always supports climate change science? Because a few regular posters who most people would not consider trolls fall into those categories.
We can (and do) go after people who are obviously trolling, but we also err on the side of not warning/banning people if it's unclear whether they are doing it to annoy people or because they believe their own woo.