High MMR isn't better players, it's better perks/builds at higher quantity
High MMR will not be just good players, it will just be everyone only running full meta builds
In my experience, meaning this is not 100% of the time and can be different for others, the actual really good players use more casual builds not the full meta, but those people will also just be matched with others being carried by their builds who are typically worse than the casual people
examples
killer - a blight that consistently 4ks running yellow add ons with something like Bbq/Agitation/Corrupt/Lethal pursuer is most likely better than a blight spamming ring/crow with Corrupt/Undying/Ruin/Tinkerer that consistently 4ks
survivor - a survivor that consistently does well running Sprint burst/BT/We'll make it/Iron will is better than a survivor doing well with DH/DS/Unbreakable/Prove and BNP/Syringes
The first builds aren't full meme builds, they are still good builds, but the point is they're not full meta builds, and considerably weaker than the later builds.
A good killer running the casual build can't do anything most of the time against 4 DH, 2 proves etc, even if they're considerably better than the survivors
As a good survivor running the first example build probably can't do much against the 4 slowdown killer running strongest add ons, even if this survivor is better and could run this killer for ages
TLDR
High MMR won't just be good players, it will just be filled with people spamming the best possible builds/perks, and will be classified as high MMR, even though they're probably worse than the people running more casual builds
Comments
it use to be that 2nd week we get our update but then they did a 3 week after PTB they basically said we can get away with that lets do it. so now it takes longer
A bad mechanic with the best tools is still a bad mechanic. People are thinking about this in the context of old matchmaking. It won't be so easy for builds to carry players with bad game mechanics when the matchmaking is better. The people I 4-man SWF with have 2 or 3 staged many bad killers with full meta in the past. Perks and add ons only do so much.
As to your point about having to run meta to consistently win vs meta: that's literally every game. If someone is truly more casual, they'll play casual and not care if they win or lose. But many people claim to be casual and it turns out they just like easy wins.
So?