It depends. I play TTRPG since I was a child, so I don't really see myself AS the character in the game, at least no 100% self insert as me, because I don't have total control over what that character is going to be. So I see the character in the game more as if I was creating a character to play an RPG, in which the DM has a bit more control over him.
I do, however, look to only play characters that at least I wouldn't mind too much interpreting in an RPG. Like, I usually prefer to make nice characters, but I don't mind being a bit evil, or a bit of a dick, or even a bit more passive, in some characters I make. As long as the character is not a boring doormat. That is at least when it comes to personality.
When it comes to fetishes I'm a bit more conservative. One example of that is NTR. I don't mind fapping to it in a hentai, or a porn, because that story is not directed at me, but it is not something I want to experience in first person, because I don't really have that fetish in real life.
That is why I prefer games where you have some more levels of control over the character, like in the Blackheart Games, where you can choose to be a dick to the girls, or be more loving, or in Fetish Locator, where you can filter out the fetishes you are not into. But when I can't have control over the personality of the character it doesn't bother me nearly as much as not having control over the fetishes, if the game has an unavoidable fetish I'm not into, I check out.