probebly wouldnt i'll be honest dont think anyone would

I mean, you're not wrong but I think in this hypothetical situation of smt being real then it's be fair to assume comps and negotiation are as well. Not saying that'd be guaranteed survival but I also don't think pulling some smt protagonist type survival would be completely impossible if such a situation were to occur.

While the validity of such tactics would be brought into question I'd simply try to keep my head down, away from the more threatening demons, and maybe have a nice hat with the weaker ones

heavy would beat all of the demon until they go back into hell

I'd probably die unless I got my hands on a COMP... and even then, I would probably lay low and maybe grind some demons. Not doing any protag-level stuff unless I need to, though.

If I had a COMP: I'd try my hardest to survive and gather a bunch of demons, and try to make my own working society, until a real hero would come to me and find some route that I appreciate. If I didn't have a COMP and there aren't that many demons around: I'd try to find the last piece of civilization and make myself useful somehow If I didn't have a COMP and Demons were everywhere: I'd kill myself so the Demons wouldn't get me!

I suppose I would sit around my own neighborhood and grind low level demons, slowly gaining my own power until I could move on and slowly gain more power, nothing big but hey, self preservation