Westworld season 3 & 4... what went wrong?

Now that the show is cancelled, I find myself wondering what caused it to go off the rails. I LOVED season 1, liked season 2, thought season 3 was a chore to sit thru, and season 4 was unwatchable.

It's not like the series jumped the shark because the main "star" left, the series abruptly changed networks or time slots, a new writing team took over, or the producer handed over the reigns to someone else. It was the exact same "team" from season 1, spearheaded by Jonathan Nolan & Lisa Joy. It's like they just randomly decided Westworld shouldn't be about Westworld anymore!

If I didn't know better, I'd swear that Nolan quit and David S. Goyer was ghostwriting the last two seasons or something...