Okay, but multiplayer indie games, everything from Mecha Chameleon to Pratfall to Yap Yap to many more like them, are hits. Even if just temporarily, these games have had a huge impact on the multiplayer scene. Friends and strangers coming together to play games that are relatively cheap compared to their triple AAA counterpart, while also having a lot of fun over the wacky physics, nonsense, and/or trolling that may occur.

You don't need cross-game features when you have people you hardly know and fun friend games like any of the above mentioned and maybe a discord call if y'all ain't in the same room.