Just because it's safe doesn't mean it's the best we have right now.
- It's massively expensive to set up
- It's massively expensive to decommission at end of life
- Almost half of the fuel you need to run them comes from a country dangerously close to Russia. (This one is slightly less of a thing now that Russia has bogged itself down in Ukraine)
- It takes a long time to set up.
- It has an image problem.
A combination of solar, wind, wave, tidal, more traditional hydro and geothermal (most of the cost with this is digging the holes. We've got a lot of deep old mines that can be repurposed) can easily be built to over capacity and or alongside adequate storage is the best solution in the here and now.