Except that its nearly impossible to get to 90% with either wind or solar by itself because when you look at the weather data the average capacity factors are really misleading. If you look at the data and say, I'm at 40% what does it take to get to 60% its many multiples overbuild. Mixing them helps a bit, but is nowhere near a solution either.
The problem boils down to the fact that you can't overbuild enough to solve the problem of the wind not blowing or the sun not shining for days at end. Which sounds uncommon but that is what happens. The wind goes gangbusters for months on end then sits there doing nothing for a week or two and your producing at <10% of the rated capacity. Sometimes you can replace it with solar, sometimes not if you have two random sequences with probabilities that they produce nothing for a while, eventually they overlap and you are SOL.
Someone should really build a proper weather + price simulation that shows what having 8x idle windmills and a couple overbuilt solar farms and idle gas-plant (which all need maintenance and their bonds paid) for 70% of the time does to the price of electricity. Because that is what happens to get to 90% when your not selling the excess/buying it back from C02 sources and then confusing people with gross consumption vs net. Maybe someone can dump all that excess power into CO2 recapture or something, but at the moment the economics are crazy bad.
And I might buy that every bit helps, but we are in many cases going backwards, doing the same thing we did for the past 10 years for the next 10 is going to be even more disastrous as its been from 2010-2020. The carbon output needs to go to 0, not 90% of what we did last year. The richer countries should all absolutely be economy wide carbon neutral, and that isn't going to happen because no one has airplanes or new electric rail, or electric plant build plans to get the 2x electric demand increase required to start actually reducing transportation and heating Co2 much less actually have a grid that only sources 10% of its energy from carbon which isn't already there via Nukes or Hydro.
And I love the downvoters who are having their feeling hurt because they don't want to believe that renewables and batteries wont solve this problem anytime soon.
So the short version is, that until you understand that a solar farm at 40% or a wind farm with an average 30% capacity factor can't produce 100% of the required generation when you 3x overbuild them, you won't understand why solar+wind doesn't work.