That is not the case. There are LCOLC, LFSCOE and others which land on renewables being way more expensive. Even without your made up claim about "assuming cheap and fast to build nuclear power".

Which are extremely simplified metrics.

Like the LFSCOE study is only using source of renewables through all weathers together with 2020 data on battery costs.

Which is why I linked a recent full system analysis. With Danish data so a vastly harder problem than a place with abundant solar. So tell me what they missed.

They even tilted the study heavily towards nuclear power and assumed that the nuclear costs are 40% lower than Flamanville 3 and 70% lower than Hinkley Point C while modeling solar as 20% more expensive.

Still finding that renewables are vastly cheaper when it comes to meeting a real grid load.