I was initially intending to send it as a private message, but there really isn't anything that would warrant it.

You are among the three or four people on this site who, for better or worse, know me more personally. There aren't many things I'm competitive about outside of chess, and even that is one of the things I think hold me back instead of helping. Most people who know me IRL describe me along the lines of 'kinda phlegmatic until you either put a problem in front of him or seriously insult his intelligence'. That's something I asked as feedback before writing this response.

I lose temper at times, perhaps more often than most people, likely less than many of my age. I don't think I raised my voice for any reason in at least a year, but it's a work in progress nonetheless.

You are correct about the whole 'being a good fit' thing. I know it, and it's something I knew for some time. But with the number of failures I had on that front, it's hard not to see myself through a prism of pissing everyone off by the mere fact of existing. The only area of my life where I feel any level of accomplishment is academia and even that seems undeserved. There's no denying the fact my social skills are lacking, but I don't think I'm that far behind either—half sigma below average or so. Perhaps I'm mistaken in my opinion, and that's the crux of the problem, but It's not like you can reliably test for those things anyway.

There's a part of me wanting to ask "how do you fake being a good fit?", but I know that's not the way to go. But there really isn't anything else for me to do. I could go full OSINT and try to devise a way of acting that would be the least offensive common denominator, but that's even worse and on too many levels to enumerate.

I'm just exasperated about the whole ordeal, though it seems like a strong word. It's more like not wanting to go back to doing stuff like overnight store restocking or washing cars while being rejected at any opportunity to improve from where I am. It's not like it can help either since it's hard to develop better social skills when the only other guy doing the job who speaks Polish (there's a lot of immigrants from Ukraine in my area) didn't progress past high school bully mentality despite having at least twenty years for it. Try Ukrainians? If my rusty-as-hell Russian was enough to gauge, they just talk shit about everyone and everything.

So what can I even do? I'm not the type that gives up easily, but at this point, it just seems polite to stop wasting everyone's time. Even I don't feel like I'm a good fit anywhere, and despite what WanderingEng said, kinda doubt that I had any merits for any of the jobs where I got to the in-person interview stage.

There's not much point to it, but I felt like you deserve some response, even if it's one like that.