Check out Forged Alliance Forever. It's a community made, open source, "launcher" for the Supreme Commander game, that patches it, mods it, allows you to interact with other players and find games and get ranked against them, and also is a replay viewer, so you can watch how the pros actually do the insane micro and economy play that earns them the 2000+ ELO score, and also a mod manager, and also a friends list.
If you are like me, and love all that but actually suck at playing strategy games in general, check out Gyle on youtube https://www.youtube.com/@GyleCast who has been casting SupCom games for at least a decade now, and really shows off some of the best that the game has to offer, including multi-hour "EPICs" that can involve ten thousand units controlled by several semi-pro players.