technically no, but realistically yes. (there is a pseudo fix in place, if you have 20% you aren't going to get a ridiculous 10 in a row, and you certainly wont go more than 5 without scoring 1 crit) we dont need RNG in league, we want decision making and predictability. but unfortunately if you make crit into stronger flat items then other champions buy it and they become stronger too.
like say for instance
if the 20% crit and bonus crit damage were just changed into raw AD, then other champions like riven or zed would pick up the item in place of something else in their kit and become that much stronger.
crit is OK at the moment, where the only real offending item is essence reaver which is 1 item with 30% cdr and infinite mana for adc's.
the only thing which could be done to eliminate crit would be to make unique items for ADC's only and melee champs only.