Never, a couple of years ago Apple gave up on the server market, that is why having Swift on Linux is so relevant for app developers.
Now they gave up on the workstation market that really enjoys their slots for all myriad of cards.
Having a thunderbolt cable salad is only for those that miss external extensions from 8 and 16 bit home computer days.
Which is clearly what Apple is nowadays focused, if you look back at the vertical integrations before the PC clones market took off.
So now if you really need a workstation, it is either Windows, or one of those systems sold with Red-Hat Enterprise/Ubuntu from IBM, Dell , HP.
If you want a workstation, you are probably better off building it yourself, or having your local computer store do it. The primary exceptions are AMD strix halos or the nvidia dgx spark.
I haven’t seen a non-laughable workstation config from the big vendors since the dot com bubble. Presumably they exist, I guess?