30,028,036 Online 9,192,320 In-Game

    Counter-Strike 2    759,021
    Dota 2              492,145
    TBH: Task Bar Hero  465,078
    PUBG: BATTLEGROUNDS 385,269
    MECCHA CHAMELEON    147,052
    Bongo Cat           144,556
    Apex Legends        122,102
    Delta Force         104,791
    Path of Exile 2     102,706
    Wallpaper Engine    96,076

I don't think the data shows what you think it shows.

It looks more like 20% of all players, not over 50% if we look at first 10 games and about 25% when we look at top 20.

Various research on gamer demographics repeatedly shows that average gamer is pushing 40 and the gender split is pretty even. Steam can't be that far off.