Depends on too many variables. Do I get a new body? Do I get an isekai powerup? If so is it completely broken, overpowered, anime protagonist tier (I'm talking to the point where I can just overthrow those in charge)? Where do I fall on the socioeconomic hierarchy? Who's in charge, what are their values? What about the general population, what are their values?
If I get an extremely overpowered isekai powerup and I detest those in power, and if the majority support those in power...then hell yes I would become a villain.
Likewise, if I end up at the bottom of the socioeconomic ladder and have to live in third world living conditions but also had an isekai powerup that, while not overpowered, gave me the ability to make money by illegal means, then I'm also going to be a villain, either the "petty criminal" kind or one of the head villain's underlings if they allowed me for a better lifestyle.
If I get the same body and no isekai powerup...then I'm just fucked. I'd just be an ugly, low IQ loser like I am now but worse since I would also have the additional disadvantage of not being able to assimilate. Not having proper documents and being unable to read, write or even talk could also be problems unless the universe I get sent to conveniently speaks and writes English. Usually in isekai anime they speak the same language as the person getting isekai'd (with some slight alterations) in the new world but the written language is different, so at least I'd have to deal with illiteracy. Basically I'd just have to kill myself in this scenario.
Also most isekai worlds in anime are dogshit if you think about it. There's generally no electricity, so say goodbye to all your copes....and basic shit like air conditioning, refrigeration, etc. Also there's usually a very large divide between the rich and the poor (far larger than what exists anywhere in the first world). The only reason they seem nice is because they're in anime that revolve around a protagonist with plot armor who meets women who help him out and really like him for contrived plot reasons in order to appeal to male fantasy.