I quit around the same time as you say you did and for mostly the same reason, and I feel like the game has improved enough to bring me back.
The cinderhulk buff and change to Scuttle Crab timing brought back tank junglers, which shifted team compositions to be more rounded and a bit less bursty. Teams with tanks have a better frontline for proper teamfight formations. I think that alone has improved the game by a huge amount. Teamfights are much more interesting than they were a couple months back, and it's because more tanks are playable again.
The meta could be better still. The damage level is still high.
Even tanks are doing too much damage and aren't durable enough. Armor feels weak except on Rammus.
Bottom lane meta is stagnant as always (all ADCs, no APCs). I think some problem champions in other positions could actually create healthy variety if moved to bot lane, like Heimerdinger (kicked out of top), Neeko (kicked out of top), Brand (kicked out of support), Karthus (kicked out of jg), etc.
Support is kind of stagnant with Thresh and Pyke being a bit overplayed. There is also the issue of full damage carry 'supports', like Brand, Zyra, Lux, Morgana, and Pyke dealing full burst levels. I think Zyra, Lux, Morgana, and Pyke support can be fine if they were dealing considerably lower damage as 'Catcher' supports, but Brand doesn't belong as a support at all in my opinion. I think Brand should be limited to carry roles in mid/bot.
Top is in a decent but precarious meta. Top still has the old problem of uninteractive ranged lane bullies, with the new addition of Neeko to their ranks. There are constant demands to nerf whichever melee top laner is top tier at a given time, but if Riot keeps caving in to cycle through nerfing all the fighters in top lane then ranged top laners may rise to dominate again. Top could also use more AP brawlers for variety. Maybe the Mordekaiser rework release will come with new AP brawler items that will bring Mordekaiser, Cho'gath, and Rumble top more.
Jungle is in pretty good shape. I am actually enjoying it a lot. Jungle tanks are strong enough to be fun to play, but they haven't caught on so much to cause people complain about a 'tank meta'.
Mid is in pretty good shape from what I can tell. I feel like if bot lane were to be opened up to APCs (which would be a good thing imo), then mid should have more marksman picks like Ezreal, Varus, hybrid Kog, Corki, roaming Twitch, roaming Quinn (kicked out of top), etc. so that marksmen don't feel pushed out of the game.