the past few seasons is what happens when Riot balances to cater to the players.
It's become very apparent that Riot is simply reacting to player complaints, instead of having a real vision for the game (this was more apparent in S4 with Morello). Slow bulky fighters not doing so hot in competitive? Darius/Garen etc players complain, we get Juggernauts. Assassin players complain? We get ADC in 2k17 lul. ADC players complain about ADC 2K17 lul? We get every other role in 2k17 lul. People complain about bruisers being too weak? We get Conqueror. People complain about not being able to 1v9 carry? We get massive damage creep and snowball, because snowballing your lane and the game off that is how you 1v9 carry. Mid players (mainly assassin players) complaining about "uninteractive waveclear lanes"? Nerfs to midlane mana sustain. ADCs too dominant in bot? We get patch 8.11. Turrets falling too fast and games snowballing too quick? We get gold plating.
Notice that some of these goals are fundamentally incompatible with the other goals. You can't have slower games and revert damage creep, but still maintain the ability to 1v9 carry (indeed, the tank metas are the metas where 1v9 carrying are the most discouraged, because even if you're a 8-0 Jax or Darius you can still get peeled, CCed and die) . You can't have bruisers and ADCs strong at the same time, because they both counter and are countered by each other in a binary fashion (either the bruiser gets onto the ADC and kills them in 2 seconds, or the ADC gets peel when the bruiser goes in, burns all their abilities on the frontline and dies to the ADC DPS after 4 seconds of doing nothing). You can't slow down the laning phase without reducing the rewards for winning laning phase (turret plating shouldn't give gold, but Riot is unwilling to walk back their response to an earlier complaint of "laning phase meaning nothing so its a compromise).
Again, all of this clusterfuckery is a result of Riot trying to compromise between whoever is most upset by the current meta, instead of having a clear vision of how each role and champion should work, how the game should flow, which innovations are healthy versus which are not, etc etc. At this point the only fix would be to just revert many of the baseline systems to season 5 (Runes at the very least), then retune and rework from there (outside creating a S3/S4/S5 server, rerolling the entire game back to that state is untenable)
