Green and purple ranks generally seem to be the worst. I've seen some white ranks that are better.
That sounds like another example of a poorly thought out port. On PC ever since they nerfed ruin survivors dont need to hit great skill checks to finish a gen now. It's why I hate investing the time to learn something and then the devs make it irrelevant.
It depends on a lot of factors. The fact that I commonly have to contend with at least 3 other devices in the same wifi, one of which is running Netflix, on Aus NBN, really doesn't help my console.
I'm sure that there were/are people who can 100% hit Greats on their console, but most of us console players are to casual to dedicate that much to it.