how about we outright REMOVE runes entirely, see how the game holds up/ the meta changes, which champs become OP and which champs disappear into obscurity.
after this, classes/champions and items can be reworked/changed so that the game can be more healthy again: reducing overall damage, making late-game champs less of a dead picks and touching up the jungle so that the trifecta of gankers/counterjunglers/powerfarmers can return.
then lanes can be fixed: abusive top laners can be toned down or moved to mid, bruiser/fighters/tank and some mages can go back to toplane.
midlane can then once again be a place for assasins, mages and other forms of mig-game carries.
bot goes back to well, being bot i guess.
while we are at it the reduction of damage will allow for the removal of tower plates, slowing down the game (the money they provide is too important).
after everything is 'balanced' to a degree, we can reintroduce runes/masteries to spice up the game or shorten game length if matches go on too long.
i say all of this because in my opinion all classes have a place in the game, and have characteristics that should be unique to them.
ADC: late-game damage carry, squishy but the best possible damage output. (hypercarries don't count under this category)
Support: stronger early, but falls off due to lack of gold/weaker items, are meant to get the ADC out of the early game. or help them in other various ways.
Jungler: a trifecta of ganker / powerfarmer / counterjungler. counter-picking and map awareness are key for this role: it shouldnt boil down to 3-5 junglers being playable.
Mages: AP/AD mid-game carries, not as strong early, strong mid then fall off a bit due to itemization.
Assassins: omea wa mou shindeiru: AD champs that are strong early with good roaming/snowball potential, but fall off almost completely lategame.
Top lane cast: too diverse to include in 2 categories.
Bruisers/fighters: champs that have medium tankiness, mobility and damage. and prefer drawn-out fights. excel at splitpushing and 1v1's
Tanks: low-damage somewhat lower mobility VERY tanky champs: excel at teamfighting, but damage falls off hard during mid-game to prevent them from 1v1'ing everyone.
juggernauts: almost ZERO mobilty, rather tanky and HIGH damage champs: weaknesses are sustain, range and kiting / initiation. should be able to beat a bruiser 1v1 (if they play it correctly), but not instantly blow up everyone (which they currently do due to the sheer amount of damage in the game.)
Battlemage: AP carry that wishes to scale up to their late game strength, but lack mobility or other roaming power to be useful mid, should be very weak/susceptible early to all-ins/ganks but are VERY strong later in the game.
Hypercarries: very weak early, auto-attack based champions with mechanics that make them stronger than a regular ADC lategame, can be found in the powerfarmers in the jungle, in the botlane or toplane.
if the game is balanced in such a way again, more interesting gameplay elements can be introduced again: until then it will remain ''X class is better than Y class because their items / stats are just so much better'' and of course ''tanks are useless, they blow up in 3 seconds''
That's all