A lot of that is because a) protests, formalities, FUD and b) lack of scale (each plant is built as one of a kind). Same for price.
With a bigger scale the construction and prices would lower significantly (as with anything done at scale), but for that we have too much populism, fear and emotional driven propaganda and gullible voters. Nuclear power always had the potential to fix the humanity energy needs relatively simply, it's sad how we got to this point.