It is irrelevant that the recent nuclear reactor projects in the USA and Europe are expensive. A weighted average of cost and completion times for global nuclear reactor construction would be dominated by the 90% of the nuclear reactors built by China, Russia, South Korea and India.
Do you based your analysis on the price cars based upon the price of a Rolls Royce? Do you price bridges based upon the cost of the Bay Bridge? Tunnels based upon the Big Dig? Rockets based upon the Space Launch System?
Also, nuclear got expensive because constantly increasing regulations and bureaucracy drove up costs in the USA. Reactors without accidents built in China and South Korea for 4 times less. Also, the systemic failure of large construction projects in the US. Skycrapers, bridges, subways and highway costs went up. High-speed rail in California versus China for costs and completions.
China generates as much electricity this year as USA and Europe combined. China will double again within 20 years. Natural gas will dominate US energy mix.
The solar and wind will not scale well beyond 10%. The US will need massive buildout of energy storage and massive energy grid modifications. This will run into the big project incompetence of the USA.