I want to tell you a bit about a game that released just over 6 years ago. It had the things you are asking for but due to various reasons things did not work out like you would hope they would.
The game had a fair number of uniquely shaped boss arenas with varied terrain. In fact the game's most difficult fight on release was set on the palm of a gigantic dragon's hand. These irregular arenas while cool had their fair share of problems; things like ranged classes being able to avoid a mechanic because they could stand on top of a pile of sand and players failing to dodge a fight's mechanics because the irregular terrain prevented them from moving away fast enough. From the second update cycle and on the designers ended up changing to flat arenas to prevent these problems.
Homogenization came about because the designers needed to insure that any balanced party composition had all the tools they needed to complete content. Early on in the games life the first fight of high end content required 2 different characters that could interrupt a mini-boss's attack. There were only 3 classes that could do the interrupt out of the 9 classes the game had. One major boss fight could be cheesed easily (before the nerf) because the boss could be stun locked by the one class that had a gcd stun.
Kiting used to be a thing in some of the high end fights, but due to their only being one ranged non-caster at the time that class became a mandatory class to complete content.
For those that have not realized it yet: I am describing FFXIV between patches 2.0 and 2.55. The designers were originally doing what you asked but problems and complaints caused them to slowly stop doing them over the course of their first expansion cycle.
Truth be told the DpS focus of this game is more the result of all high end fights having tight hard enrage timers. Its hard to not be dps focused when completion of a fight is more determined by doing X amount of damage before X minutes are up than being able to repeatably do mechanics.Every class is tailored around DPS numbers because every activity in the game gravitate towards this dicretion. By patch 5.1 we will probably be playing 3 jobs instead of 3 roles, the differences being just in rotation nuances; the question that worries me is: what will happen in the next patches? Will we ever reach the desired “perfect and purely balanced” world, where in return it doesn’t matter at all which job you choose to play?