Why not just advertise what it is that you are looking to run? Just filter people out, with your pitch. "I am looking to run game "X", via ruleset "Y", with true old school sensibilities. If you can handle that, and that sounds like fun to you; let's try to set something up.
Then any further filtering, can take place in private.
Look at my sig. I lay everything out, extensively list what I want to run, what I'd prefer to play. I went out of my way for clarity.
People simply don't read.
If I can presume to try and read Jam's mind, the usual procedure in the VTT world is to do your posts with a specific campaign pitch. i.e., "I'm running X kind of Campaign with Y system, at Z time, and I need XX number of players." I think he just meant you might get more frequent/reliable applicants that way, rather than with a general game-group listing. You might have better luck advertising specific campaigns first, and then using that to build a player group.
That's kind of what I did, without meaning to. When I started on VTT I didn't have time to GM, so I just went looking through Roll20 for games to join. Currently I have two games I play in (with a third possibly starting soon) and one which I run. In my game, all but one of the players are people I invited over from games I was playing in. Between my player games, I've got a network of about 12-15 people that I can invite into future games already knowing they're solid players.
The thing about game selection is that certain games are biased towards certain player groups. What I mean by that is that I suspect a lot of grognard types only play OSR games, not because they aren't willing to try other systems, but because they know that they're more likely to get the kind of players they want in those games. Personally, I'm willing to try almost any system (other than PBTA, which I have tried and did not care for), but I'm much more willing if I know some of the people involved. I'm pretty reluctant to apply to join games in the more popular systems (5e, Pathfinder, CoC, even Savage Worlds to an extent), because I know that I have a high probability of winding up in a group with players that are likely to annoy me.
I do think you're probably pretty badly restricting yourself demographically, too. I saw in your other post you specified Gen X or older Milennials with a lot of free time. My sense of VTT players is that a lot of them take to the internet precisely because they have a restrictive schedule, which would make it hard for them to do home games, and Gen X and older millennials (which I take to mean around 35-55 years old) are right in the time of life when they're likely to have the least free time.
Speaking for myself again, I took to online gaming precisely because I had an (at the time) newborn baby and a more than full-time job, and could only play after the kid went to bed on weeknights.
I wish you all the best with it, though, as someone who was in a somewhat similar position not that long ago. Frankly, if you've got two games on the go, that's pretty good in itself. Online gaming seems to have slowed down in the last year or so. When I started it in early 2021, I was pretty spoiled for choice, but I've been hunting for another game to join for the last few months and only just found one a few days ago.