There are good solutions for combining multiple faraway players into one draw call. You first lod them and then copy them into the same vertex buffer using a compute shader. Afterwards, you can render something like 8 reduced poly players with the same performance as one full-poly player.

But, that method is difficult to get right in Unreal Engine and impossible to do with Unity. That's why you only see it in high end titles like Battlefield but not in any indie MMORPG.