What do you think of on-hit itemization?

Now that I have seen a lot of Varus building , I want to share my opinion.

On-hit itemization is not very good. People complain about AP itemization being bad, but on-hit items are even worse. You have even less options and most of them have serious problems.

scale very poorly during the game isn't bad but require AP stacking to be useful is good, but it requires HP stacking and only melees can build it lost its on-hit effect recently is good, but only junglers can build it I don't think I need to explain why no one build this. is too expensive and it is hard for melees to use this effectively. Its stacks also decay way too fast. is technically an on-hit item but its on-hit effect does no damage, so it doesn't count. is actually the only on-hit effect that doesn't have any problem. It is good and doesn't have build restrictions. Every on-hit champion uses it well.

For many on-hit champions it is better to either go crit, or focus on some other builds that allow them to be viable. Jax for example, is supposed to have insane synergy with Guinsoo's Rageblade, but he prefers to go Titanic Hydra because that gives him waveclear and a better mid game.

Sometimes I wish that Riot gave a look on on-hit itemization and on-hit effects in general. Some things that on-hit items are lacking are sustain and, for melees, waveclear (there is Titanic Hydra, but not all on-hit champions want to stack HP). Penetration is also an item that on-hit items do not have, although because most on-hit champions deal mixed damage, it can be difficult to balance penetration for them. Peharps giving them flat penetration could be a good choice? This way, they can be good against squishies and tanks can stand a chance against them later in the game.

What do you think?