I agree. When Riot was reworking him back at the end of season 4, his ult was one of the first things to go. It might have been special back in the day, but now it's really mediocre. If you want the revive portion of the ult you can always play
and do it better. If you want the clone portion of the ult, you can play
and do it better. In the best case scenario, Yorick's ult would be both unique and effective. But if I had to choose between the two, I'd want effective. Let the rest of his kit be the unique part in that case.
Fun fact: The season 4 hypothetical Yorick ult let him put down a tomb on the map that constantly spawned undead. These undead would act similar to empowered minions by pushing the lane, taking towers, and making split push Yorick more effective. Does that sound familiar to anyone?
It was unique, effective, and it stayed true to his theme of being a gravedigger/necromancer. Now that the portal exists that ult wouldn't work well anymore (or maybe it would work TOO well, if he had both) but there's definitely room for improvement in Yorick's ult.