PC games would allow everyone to play with whatever controller they prefer.

In general, mainstream/casual audiences will enjoy games like Fifa (or maybe the NBA or NFL equivalent since you’re US) and, if you’ve got a Nintendo console, Mario Kart is a very popular casual tournament game with the option to play as teams as well.

If the participants play shooters, things like (older) Call of Duty games, Overwatch, and maybe Fortnite for more modern audiences are decent options. If they’re more competitive, Counterstrike 2 or Valorant are good as well. Retro Gamers might like Halo or Quake as well.

If they’re into strategy you could play Civilization or Age of Empires, though those games might take a bit long.

For Racing Games, Trackmania is a Time Trial game with a Hot Seat mode, where players take turns trying to drive the fastest time on a track with a time limit. Otherwise, Sonic Racing could be an alternative to Mario Kart that’s available on PC, or you could try a Sim (Forza Motorsport is good for controllers and has split-screen, Assetto Corsa is a more hardcore Simulator which would require multiple setups)

For fps: cs2, valorant, cod

For moba: dots, overwatch 2, League of legends, deadlock

For RTS, Aoe2, aoe4, starcraft, Warcraft 3, beyond all reason

Some fun events could be osrs pking tournament, classic shooters like halo, quake, unreal, kart racing games fighting games like tekken, street fighter, guilty gear, mortal kombat

Team games are harder than 1v1 because getting all the teams together is like herding cats and following the action of all players is challenging. Probably best to do it all on PC and rent 12 PC's for the day. People can bring their own controllers and play that way if they choose.

Ask about best pectoral physics to separate the wheat from the chaff

The short answer is something people can play on a phone. Console ownership is not so prolific that you can assume people will have them, or that they will know how to use them properly. To that point the jackbox games are great for this