You win debates for onlookers, you're not meant to change the perspective of the person you're debating, you're meant to make them look like idiots so that any lurkers who quietly agree feel bad and change their viewpoint. The left lost because they weren't willing to do this hard enough.

It unfortunately also not a thing in real life. Tried to convince my mother's partner that transphobia and homophobia is bad. Best I could do is to him admit it was not about "protecting the children".

If it were constructive it would be called a discussion, not an argument or debate.

It is possible, but especially in the bigger communities its usually just throwing poop at each other(that's at least my experience).