Alright so I have over 2000 hours in this from Middle and High school. For about those first 100 hours it can be pretty fun with friends. Like most of these online multiplayer games, there is a demand from the publishers to make it into a sport and a casino. Your competitive friends becomes annoying and your gambling addict friends sink themselves into a hole of sunk cost. I know guys that spent literally every dime they made working fast food on CS:GO lootboxes. Genuinely depressing to see.

I never personally got into the ranked mode of any of these big multiplayer games. I'm not that competitive and I had enough fun in the normal mode with friends. The game is fun with friends because doing anything with friends is fun.
The gameplay isn't that incredible. There's a lot of interlocking systems that are rewarding at the absolute highest levels of play, but for casuals is rarely satisfying and often frustrating. I do think the basic movement and camera operation becomes satisfying once you get used to it.

I'm not going to claim the game has "gotten worse" over time because frankly the game has always sucked pretty hard. When I revisited the game (once in 2021 and for about a month in 2023) I found that a lot of it had lost its charm. There were a lot of QoL and visual updates that looked quite nice, but overall the artstyle had taken a plunge. My favorite characters to play were the monsters, yordles, and the undead. I played a lot of Cho'Gath, Veigar, Karthus, rework Sion, pre-rework Shen. These all have pretty vibrant designs. I think the design team was especially bringing heat around 2014-2016 with champions like Bard, Tahm Kench, Rel'Sai, Ekko. I'm being unironic here saying these are some of the best character designs of all time. Recently the designs have taken a depressing turn. I think at some point Riot realized that the most popular characters were the "hot" ones, so nearly every character since around 2017 have been anime/pixar stylized husbandos and waifus. The kits have also become absurd with overtinkered abilities and overcomplicated passives. There was something special about the simple champions of yore. Champions like Cho'Gath who have abilities that do 1 thing instead of 20 make the game far more enjoyable to play IMO.

Even at (what I consider to be) its best, it's just a waste of time. There's so many better options for co-op and multiplayer games. If you want to scratch that competitive itch join a sports club or something. If you can't do that play Tekken. Need a way to spend your free time in High School/College? Learn an instrument. Pick up a craft, an art. Play one of those huge Yakuza or Persona games and ignore your studies like a normal human being. Don't play this game.