> At minimum you have to filter out 90%+ of people that simply don't have the mental faculties to evaluate what is and isn't a valid argument, before you even get started.

I don't think this is true. There are times when I do think it's true, and when I start feeling that way I know it's time to step back because I can no longer engage constructively.

Text is a hard medium to have a back-and-forth in. The features that make it useful for explaining also make it easy to feel ignored and insulted.

I think a lot of people also go online and write things when they feel argumentative, so comment sections self-select for people who want to argue.

Whenever I feel intellectually superior to someone, I try to remind myself that I can barely change the oil filter in my car, and there's a lot of people out there who can't write a line of Python but who save tens of thousands of dollars doing their own maintenance.