One exception to this is the Coven of Shivarra mythic in Antorus (purely because the damage reduction buff they gain, and the increased HP). Some classes could manage it (e.g. locks and hunters), but most classes had a difficult time separating them for long enough to get significant damage off. High Botanist in Nighthold can also be a major pain to deal with due to the mechanics, but it's absolutely possible to burn them down before the debuff 1-shots.
I'd say that navigating parts of Antorus can be a bit confusing at times, but it's definitely not something I'd ask them to change. They can easily change balance for player that have outleveled the content, whereas changing the instance geometry requires huge resources (significantly more than the time it would take for someone to learn the routes).