I think the art design in BFA is overrated. The tier sets are awful. Compare the tier sets to Vanilla or TBC tier set. The zones are way too cluttered and the layout in zones like Nazjatar is terrible. There is actually too much detail in the zones. This was an issue in Legion as well. You can't see 10 yards in front of you without being impeded by some piece of terrain or object. Part of the reason it is hard to see other players in the zones is because of how detailed they are and designed. There is too much going on. Think of a zone like Shalozar Basin or Nagrand. There are a lot of wide open flat spaces, which makes it easy to find other players. There are so many elevation changes and roadblocks in BFA zones that it just isn't fun to walk around on them. There is also no sense of scope in the zone design anymore. Blizzard tried to make every encampment, building, or gate look grandiose. When all the quest hubs and landmarks in the zones look so imposing it ends up having the opposite effect than what is intended.
Warlords of Draenor for example added a lot of dumb features to the game, but Draenor itself was quite well designed. Compare the revamped Nagrand or Gorgrond to what we got in Legion or BFA. They were way better zones.