Saying nuclear is unfeasible because building new plants is too expensive and takes too long is like saying swimming is too hard; but then it turns out you insist on carrying a 100lb anchor whenever you get in the water.
The reason it's expensive and takes a long time is because of the absolutely massive amount of red tape built up over the years. Some red tape is obviously a good thing, but fear around the word "nuclear" has caused so many unnecessary regulations, committees, and testing that it causes plants to take 5x what they should cost and 10x the time.
Literally having to build safety mechanisms and procedures for failures that aren't even physically possible. All because the average person knows jack shit about nuclear power.