There's a solid list of major changes that Riot made to change the game (Not in chronological order)
- Elemental Drakes
- Jungle Camps
It's getting exhausting.
I understand "keeping the game fresh", but true sports don't see that many changes once the game is established. League is 10 years old. It's getting to the point where major changes shouldn't be expected. This round of Dragon changes are pretty extensive and even change the entire map.
At a certain point, Riot, you're just making the game more impossible to balance for that sole purpose. It's less about being fresh and more about change for the sake of change. Change is necessary, but not all change is good.