I'm saying you can get to 90% yes.

But, as often happens, the last 10% is as hard or harder as the first 90%. The law of diminishing returns.

There are lots of answers to steady-state that are green and won't take 15 years

I'm aware of and have studied them. But general public seems to greatly underestimate the scale of storage that's needed. Germany, for example, consumes about 1.4TWh of electrical energy a day. That's more than the world's current yearly battery production. It does not suffice to power Germany, for one day.

Pumped storage, if geology allows for it, seems like the only possible technology for sufficient storage.

Demand side reduction is possible as well, but that's simply a controlled gray out. The implications for a society are huge. Ask any cuban or south african.

Others, like lithium ion batteries, green hydrogen, salt batteries, ammonium generation, ... have been promised for decades now. Whilst the principle is there, they do store power, it simply does not scale to grid scaled needs.

The sad part is that it sets a trap, like we in EU have fallen into. You get far along the way, pat yourself on the back with "this windmill powers a 1000 households" style faulty thinking. But as you can't bridge the last gap, your reliance on fossil fuels, and total emissions, increases.