To be clear, I've hated auto-scaling for literally decades (e.g. Final Fantasy 8).
While the goal of having all content be useful at any level is a good idea on paper, it's extremely difficult to tune right. The normal outcome is to have enemies get stronger as you level, which goes contrary to all power gain concepts. The 'best' result is usually to have enemy strength remain flat vs your level... which makes all player power gains (and time spent) irrelevant.
(The best system imo is what was in use in Fallouts - if player levels range from 1 to 100, Deathclaws in area X scale from 30 to 60. So the level 1 can't be useful everywhere and gets bodied, encouraging them to gain power before returning, but the 61+ crowd still gains power vs the enemies and (eventually) rewards power collection. But you've now rendered that content non-optimal for levels 1-29 and 61-100, which is broken to the 'scaling everywhere' design crowd.)
Again, Remix has two problems.
The first is that the instanced scaling at 60+ is broken, or at the very least heavily desires a full set of the jewelry achievements and their rewards, which nothing in the game told players they were intended to get before that point.
The second is that it doesn't give players ANY indication of what the level 70+ progression should be. Apparently players were supposed to spend mass quantities of bronze by doing dailies and repetitive decade old content for weeks if not months (in a mode that only lasts for three months) until they could do Heroic / Mythic raids to earn more Bronze than they spent on upgrades quickly.
Well, three now: when players realized the two issues above and tried to remedy them by killing enemies to increase their personal power (e.g. frog farming) as instruced by the mode, in the same method people had been using for a decade, Blizz became alarmed people wouild get done with the mode sooner than their engagement metrics wanted and reverted their power gains, despite zero communiction that this was unintended. As someone who didn't kill a single frog, I still think that sets a horrendous precedent that Blizz can and will retroactively nerf you, with no warning, if you outpace the accountants' intended power cuves.