Why not class restrict lethality to Assassins?

If it's such a massive problem, then why not just mechanically restrict the stat so that it can only be used by Assassins that Riot white lists for the stat? It was done for items like Ravenous hydra and Runaan's, so I don't see why riot hasn't explored that route more yet.

It's definitely not a horrible idea to think about.

You could have a specific set of items designated to a specific class. Then inbetween you could have lower tier items that would offer some of the benefits of restricted items but with much less gain.

Examples: Randuins Omen and Spirits visage could be restricted to designated champions that focus solely on durability.

Items like Black Cleaver, Titanic Hydra, and Frozen mallet would only be available to designated juggernauts, bruisers, and dive fighters, all classes that are focused on skirmishing and damage with survivability.

Lethality items or maybe just the stat itself could be restricted to designated assassins.

Then somewhere in between you could have lower tier generalized items like Ohmwrecker that offers the same sort of role as similar restricted items but with no where near as much stats.

At the very least it seems more appealing than this cycle of something somewhere getting abused only for that specific mechanic, item, or stat to get ran into the ground with nerfs which would result in burying other champions that were connected to it.