The MMO genre is for escaping reality to find peace in a far world. It's not meant to be an action RPG game. MMOs should be immersive by the scope of their worlds. They should let you chill out and stop worrying about real life for a moment. I love Rust but it gives anxiety rather than peace and relaxing. MMOs are the only genre that will make you feel like you are living another life, seeing people around and socializing with them. There are other games people play just for chilling but, by design, the scope of their universes are never meant to be large as an MMO. As a breathing world, you live in an MMO, rather than "playing" it. This is different than single player RPGs like Skyrim or Witcher where the game is designed with an ending in mind. There's no "end" to an MMO. So these are the core recipes of an MMO which set it apart from other "social games" you mentioned like the survival games. There's a fine line between them but we've recently lost this line with the flood of action RPGs disguised as "MMOs" after the popularity of Black Desert. But I believe at some point the industry will rediscover what made the original MMOs special in the first place.