Transitions take time. We can't just flip a switch from one technology to another. What we are seeing is that the cost drop over the past decade for wind/solar/gas is so drastic that coal and nuclear are simply shutting down, because it's cheaper to shutter the plant than to keep it running. Electric utilities are taking multi-billion dollar writeoffs, because that tech is obsolete.
Nobody is building coal plants now, period. Most of the nuclear projects on the drawing board are getting canceled before ground is broken, because they can't hit the necessary price targets.
The main problem with nuclear in the west is mismanagement and loss of skills amongst construction and engineering staff. Many countries haven't built a nuclear powerplant in decades, and are having difficult now.
China is doing much better, and so is France and even Russia is doing ok, as they have a larger and more experienced workforce regularly building reactors.
I live in the UK and for the past decade every major construction project I can remember was massively delayed and over budget. Currently its HS2 and crossrail. So the faults don't appear to be specific to nuclear in industry.
Nobody is building coal plants now, period. Most of the nuclear projects on the drawing board are getting canceled before ground is broken, because they can't hit the necessary price targets.