I have friend that's currently playing in two Rolemaster games and a MERP game on Roll20, so I know other options are out there. I'll ask him if there's anything special he searches for when looking for such games. However, it might help if you specify what games you want to play.
I'm just not finding places to even look for games, other than Roll20. Roll20 has hordes listed -- true -- but 90% are 5e or Pathfinder. My plan if nothing else worked was just to keep checking there until something comes up. We're also limited by playing Saturday or Sunday (possibly Friday if the timing is right) and we're Central US time. We have real full-time jobs where we get up at 6 each morning, so we can't really game until 2 in the morning.
I was trying to avoid the issue you sometimes get where, if it isn't on the list, people won't recommend it. However...
We prefer rules light games (which if automated by VTT can be a bit crunchier I suppose). BareBones Fantasy is our favorite because of how it encourages role-playing. We like to role-play and roll dice.
Some examples we like are: BareBone Fantasy, BFRPG, or some of the OSR/older DnD type games (S&W, C&C, ACKS, etc.)
We'd love to try some version of Traveller (Cepheus / 2d6) since my wife has created lots of characters but never played.
I don't mind Rolemaster as a system, but would need some hand-holding during character creation if the other players are the kind that know how to max out skills based on stacking otherwise unrelated skill choices. (Something I ran into 30 years ago playing it.)
FATE isn't on the list, but I wouldn't mind trying it. Same with Call of Cthulhu or lots of other games.
More important is the kind of GM or style of play -- something where the GM is challenging the players and helping them to have fun, not just trying to kill them.
A game/campaign with some sort of plot is preferred -- I'm not sure how either of us would deal with the sandbox that seems so popular. But we're willing to try.
A group where they're trying to have fun, not one-up each other or put one over on the other players.
No "adult content" -- so, not one of Venger Satanis' games or Gor. (I have several of VS's adventures and most of the Gor books -- just not what we want to play.)
Trying to avoid politics, so leave it at a group where they aren't going to ask us our pronouns.