The whole shards system was incredibly rushed. They’ve been scrambling to catch-up. I don’t know what put them so far behind (COVID hasn’t hit other devs nearly as hard).
I really do like 9.1 and I do like the set bonus powers themselves and the overall feel of loot in SoD, but the Shards are just so janky and ill-conceived in their implementation. It was very obviously rushed when they were patching core features of the mechanic as hotfixes post-launch of the patch.
Most leather-wearing / agi-based DPS don’t get any weapons from the last two bosses. Cloth casters get a staff and Strength users get a 2-hander.
The spec that comes out the most ahead is - drumroll please… MOONKIN.
Everyone else suffers in one way or another, whether it comes to sockets, bad loot tables form the raid, etc.
Even balancing? Have you looked at the raid loot table? It’s kind of a mess. It’s pretty obvious Blizzard isn’t aiming for “even balancing”, they’re aiming for “Just put stuff out there and players will figure out what’s good”.
No, they also weren’t restricted to only certain zones. We don’t know where the story is going but with 4 sigils I don’t think the Jailer is stuck in the Maw anymore, so domination socket gear would need its own plot device to remain important.
Outside of the Maw content not all the shards are equally powerful. The socket bonus would need to carry on in 9.2 content to keep all the shards relevant.
The HoA was the backbone of all BFA content, it wasn’t expected to only be restricted to Eternal Palace or such.