Yeah, I never understood why that was necessary. I get diminishing rewards as an addiction mechanic, but they all switch gameplay dramatically from adventure and exploration (and combat) quest based character growth to raid fueled gear treadmills. Some people live for the latter it seems like? But there were never any that focused on character growth all the way. It wasn't like they weren't adding content continuously anyway. It would have been possible. Or turn it rogue alike with top levels earning benefits or unlocking other options for additional playthroughs. With the number of mmorpgs made one of them would have tried it if it would jave worked I guess?