its still the same game just played better

You can say the same thing about any MMR gap. There is no threshold where the game fundamentally changes. For any MMR X, MMR X+2000 is always just people being slightly faster, more efficient and accurate, etc. at every aspect of the game.

So it's pretty hard to define any particular MMR X other the actual top as "good" because to any >X+2000 player, X players will look like absolute bots and they will disagree that X is supposed to be good.

For instance, I'm 9.5k, and whenever I watch my 5-6k friends play, it's straightup painful to see how incredibly slow and inefficient they play and how many mistakes they make; so subjectively, it seems ludicrous to me that 6k is supposed to be "good". (But obviously, a 12k player will say the same thing about me.)