This has been a reasonable point to bring up. Renewables when they are first coming into the system represent only a small part of the energy supply. But as they get bigger, the swings in availability end up swinging the entire system around to a larger degree. This is usually where Gas plants take up the slack trying to balance out the system. Storage is the key.

I suspect this is an issue that looks worse in 'intuitive' foresight but not so bad in educated retrospective but we will not know until we pass through that point. I am but an armchair "expert" on this. Usually when something like this comes up, 15 people who know better than me will highlight something I was not aware of.