I would hazard to guess that latency would be a killer for that. It's painful enough if you have 100ms ping on tactical FPS games like CS:GO for instance, but if the delay in a player's position updating caused a completely different physics cascade to happen (running into a wall rather than a stack of cardboard boxes for instance), that could get pretty jarring to see either the correction occurring constantly or the physics delayed after someone's actions.

Of course I'm just theorising - it could be an idea that no-one's implemented yet.

A lack of gameplay from the resulting physics to justify the server costs? Game devs don't simulate worlds for the fun of it. They have a purpose behind things. There's a cost/benefit involved.

> Game devs don't simulate worlds for the fun of it.

Unless you are Tarn Adams

Or about a thousand other small indie devs, but somehow I don't think Stadia has much interest in them.

P.S.: Don't take this statement the wrong way, I love small indie devs and donated for Dwarf Fortress.

The technical difficulty of making an MMORPG I'm guessing.