Their compact solution doesn't cover all needs, they just decided that they didn't care about some of those needs. The Intel Mac Pro was the last Apple offering with high end GPU capabilities. That's now a market segment they just aren't supporting at all. They didn't figure out how to do it compactly, they just abandoned it wholesale.
Similarly if your use case depends on a whole lot of fast storage (eg, the 4x NVME to PCI-E x16 bifurcation boards), well that's also now something Apple just doesn't support. They didn't figure out something else. They didn't do super innovative engineering for it. They just walked away from those markets completely, which they're allowed to do of course. It's just not exactly inspiring or "deserves credit" worthy.
You could argue they abandoned that market long before (around the era of the mac pro trashcan). Along with the pro software.
They can abandon it multiple times ;)
When they introduced the cheese grater Mac Pro the new high end GPUs were a showcase feature of it. Complete with the bespoke "Duo" variants and the special power connector doohickey (MPX iirc?). So I'd consider that an attempt to re-enter that market at least.