The argument I have generally heard is consistent power output and grid availability 24x7 with solar is harder. So they augment with gas turbines.
IMO augmenting it with nuclear is better.
Augmenting intermittent renewables with nuclear doesn’t really make sense since nuclear is all fixed costs whereas gas generation is mostly fuel costs which makes it economic to run part of the time.
And even better is to augment it with large scale batteries.
Nuclear is fine, but very expensive and very slow to deploy.
Why not just nuclear?
Because it’s too expensive so needs peaker plants. Or batteries.
Why not just gas?
Because it’s too expensive.