They never knowledge their own strawman.
And in some fun cases they set up a straw man, then accuse their opponent of doing it, so they can hide their own.
It’s kind of fun to watch from afar, but annoying when you’re the opponent - because it’s a straw man plus red herring, and yet if you call it out people will understand it as a “NO! U! WAAAH”, even if that is not the case.
The sign they know they’re wrong but don’t want to concede defeat.
Sometimes it’s about not conceding defeat in the debate, I agree. And sometimes it’s about convincing people that the proposition is true - sometimes the others, sometimes themselves.
You see the later a lot when people are witch hunting (accusing someone without solids grounds to do so), and the person is actually able to defend themself, or someone defends them. Often the attacker show signs to still genuinely believe that the person being attacked should be attacked, regardless of how you prove them wrong, because they claim that you’re straw manning while doing it.
[Sorry for rambling about this stuff.]