Both Guinsoo's and BotRK Give Stats That You Just Don't Need On On-Hit Champions

BotRK has AD, most on-hit champions don't really scale all that well with it though. That's why they pick up on-hit and attack speed in the first place. Another confusing aspect is that it gives you life steal. As an on-hit champion, you don't really want that either, since you obviously can't lifesteal off your on-hits and your basic attacks themselves don't really deal a lot of damage compared to most crit champions, who also don't pick up BotRK to go for a BT instead.

Then there's Guinsoo's. It's kind of stuck between being an on-hit item and a hybrid item. There are not a lot of champions in the game who can make perfect use of AD, AP attack speed AND on-hit all at the same time. The only one I think does it somewhat good is but even his AD ratios are somewhat meh compared to others.

for example wastes way too much money on AP and he only has a shitty ratio on his W, scales rather horribly with AD and does not want either on-hit or attack speed.

I'm writing this mostly because both items get just straight buffs on the PBE instead of making those items more linear and actual full on-hit items.

I personally think Guinsoo's should get rid of either its AD or its AP or both and it should have more attack speed or its gold cost lowered instead, otherwise it'll always give a much too weird combination of stats to really work as an item.

BotRK could also get a kind of mini-rework, maybe so that is has actual on-hit sustain instead of life steal.