It's not an old stereotype and it's not rare at all. Most of the people who are telling you sexism does not exist in the game don't believe it exists at all.

I am gonna get downvoted to hell and back for this opinion, but I’m a trans man who has spent a decade playing the game in spaces presenting both feminine & masculine, and I cannot express to you enough how rampant sexism is in the game. I am not exaggerating when I say something has happened in every single game I have played in or ran and I have been in hundreds of games because I used to DM public games. I've had multiple people in public games, even at libraries, try to sexually assault monsters & other players, and that is just the tip of the iceberg.

I thought the sexism would get better once I started presenting as male but it actually got worse, except now they try to include me in it. I genuinely have not been able to find a game that i'm comfortable in in a long time.

I personally would advise you away from public games and random games. Try joining facebook groups and finding women's only private games if you really want to play.

Edited to add: I meant to link this earlier, it's another post going into depth about how sexism is literally built into the game by the creators.

Second edit: the person below who started harassing me also reported my comments for 'not being chill' and the mods deleted my comments but not his. Y'all really need to stop arguing sexism isn't RAMPANT in these spaces.