Everything said, I still don't know if they are in introducing something dumb every gen or just looking for something that works.
- Megas were awesome, but they were also broken and miss handled in gen 6. Besides that, making megas for each pokemon would be a lot of work.
- Z-moves also had design problems, besides the dumb animation. Any attack with a base power of 70-75 became almost an hyper beam with a z-move, without the recharge turn and always hit, even going through protect. And that's for weak attacks, so they were kinda broken. On the other hand, because they were 1-off, if the opponent swaped to something that had resisitance to it, it was really lame to lose it that way.
Dynamax does seem like a match between something that could be easily applied to every pokemon, can't be easily denied since it lasts for 3 turns, but it is also not permanent for the whole battle, so the opponent can just stall with protect/dig/fly. And also gives something for players to do in group.
But yea, it looks dumb.