Why can't the game have themed and interactive events like other competitors?

While every other F2P live-service games have multiple seasonal events with festivities and various game modes, this year League of Legends has been a museum of battle pass and prestige skins that require you to do the same thing over and over on the same exact map. With the annoucenement of all other games Riot had in store, it feels even more like the actual main game has been completely left out to be bland and impossible to innovate. Why not focus resources and assets to create things like the Bilgewater and previous Star Guardian PvE event? It never feels like the game's events are anything, they're just visuals on the client but nothing ever happens ingame. Heck, even Wild Rift is getting visual updates for characters but somehow those updated assets won't make it into the main game. At what point do we do anything else than mindlessly spamming 30 minutes games on the Summoner's Rift? There's nothing ever hyping to look forward to in the game anymore other than skins and new champions...and that gets old really fast.