What is more reliable to you then....
For a small example, to name one situation, each of these champions is going for a kill on a lone enemy, who do you think will have the hardest time closing the gap AND unloading their damage onto a generic target.
A rengar ulting and autoing someone + q for a quick and easy kill.
A zed with his large engage radius with w r.
A talon whos main damage source is also undodgeable, along with plenty of mobility and invisibility and a small dash to target
A kassadin whos main damage source is also undodgeable and also has more mobility than lee which requires no skillshots.
Or a leesin that needs to land his q which can be blocked by minions. (even with his wardjump, we cant say for certain that he can reliably land his Q due to the generic opponent`s ability to walk around , making his q hitrate <100%)
Looks like the leesin isn't as reliable making him unreliable by comparison therefore it is grammatically sound when comparing leesin to other assassins/similar champions
If you are going to insult me as an individual, go ahead, it doesn't stop me from being correct.