ADC
I am and have always been an ADC main so forgive me for bias that is present in this discussion.
The main problem that I see a majority of people complaining about ADC's is that they deal too much burst damage.
Also people say that the main goal of the ADC is to shred tanks.
If an ADC is supposed to shred tanks how could they not obliterate squishies as well?
The only possible way to do this, that I can think of, is to make auto attacks deal % health damage. That way they shred tanks but not really squishies. Crit could be removed in this scenario.
Now I'm in no way capable of doing the math needed to try and calculate a logical formula to convert AD into a % damage.
This isn't a great solution (obviously) but I'm not certain there is really another change that could make squishies tankier than tanks for one class.