Your logic is the wrong way around, simpler champs should generally trend higher winrate-wise even in soloq even without being OP because they’re easier to execute on. See malphite for example, even when he’s in a balanced state he still tends to hover around 51% winrate.
Maybe I’m misremembering but IIRC I didn’t really think it was all that fun when it was meta. You were vs. 2 health/mana bars before first base and even if you chewed through them they’d just base and tp back with dark seal. The answer was basically to either fully all in or just accept that the lane isn’t really gonna go anywhere until lvl 5+