The other major issue, in my opinion, is that ranged classes have virtually no DPS while mobile. Except BM Hunters. With healer throughput so low compared to damage taken and the size of health pools, you can't allow your non-tank team members to stand in the fire to continue DPS. It's just doubling down on tanks being superior options for us in Mythic+.

The good news is that you can get the same ilevel from WQs as you can even doing Mythics, albeit slower (Weekly outdoor boss helps a lot). I'm leveling Warlocks with Priest healers now. Gearing will certainly be slower than the DK plus Pally team, but I'll end up in the same place.