Can we stop pretending itemization isn't a problem?
I'd go so far as to say poor itemization and its scaling is a large part of what has pushed this game into a one-shot meta.
Every time a single role is dominant, the answer has always been "kill them before they kill you".
Now we're past a point where tanks were nerfed for stat-checking everything that couldn't kill them fast enough...but their tankiness was nerfed instead of their damage, and ADCs have been made into burst+dps champs...without the help of crit itemization.
Can we honestly just scale everything back?
Make the majority of mages fall off past mid-game. Make the majority of ADCs shine exclusively late game. Make tanks able to front line again. Make assassins compliment poke comps like their design space suggests, rather than straight-up 100-0ing you.
Like, there is so much room for clear, identifiable roles for the majority of the roster, and they're all being shoved into this hyper-mobile one-shot fiesta instead. Variety in this game is dying because almost half of the champions in the roster don't get seen outside of once every 50+ games because some other champion does their job (remember, everyone's job is to 1 shot now) better.
Itemization, scaling, etc needs to be overhauled entirely to place champions back in their designated design space.
Give champions/roles actual jobs to fulfill instead of everyone thinking that they're the one that has to carry the team on their back.