I fail to understand how one may think nuclear as part of any realistic approach.

For one cranking up new reactors became too difficult a long time ago. France (Flamanville-3 https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan... , also in Finland https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#... ) and the US (Vogtle https://en.wikipedia.org/wiki/Vogtle_Electric_Generating_Pla... ) projects are horrifically over-budget and late.

China, often presented as building reactors at a fast pace, only produces about 6% of electricity with 50GW nominal electric power, and long-term plans for future capacity are up to 200 GW by 2035 ( https://en.wikipedia.org/wiki/Nuclear_power_in_China ): 7.7% of predicted total electricity generating capacity. Given that their previous long-term plan failed flat this meek result even remains to be seen.
China already has 253GW solar and 281GW wind (plan for combined solar and wind: 1,200 gigawatts by 2030) ( https://en.wikipedia.org/wiki/Solar_power_in_China , https://en.wikipedia.org/wiki/Wind_power_in_China ). Even taking into account the load factor seeing there some 'nuclear renaissance' seems difficult.

Then there is peak uranium. "identified uranium reserves recoverable at US$130/kg ((...)) At the rate of consumption in 2017, these reserves are sufficient for slightly over 130 years of supply". It means that quadrupling the meek world nuclear fleet (which provides about 2.5% of final energy) would limit, under current conditions, the lifetime of all reactors to about 30 years. Betting on some new way to quickly obtain huge amounts of good uranium at low cost would be funny, as the uranium bubble of 2007 massively bumped up exploration with tiny results (+ ~15% up in reserves). Good luck to finance this.
https://en.wikipedia.org/wiki/Uranium_mining#Peak_uranium

Strategy also chimes in. Nearly all uranium mining is, directly or indirectly, under the aisle of a politically-loaded power (either Russia, the US or China): https://en.wikipedia.org/wiki/File:World_Uranium_Mining_Prod...
Therefore nations trying to reduce their influence on them will try hard to avoid becoming dependent on uranium, and nation accepting this will only bet if the power also bets on it, enforcing the uranium peak.

Waste management remains a major challenge. Not a single nation solved it. The more advanced ones (Finland and Korea) don't even enjoy a working solution for the lifetime of their current reactor fleet.

Then there is the NIMBY effect.

Add risk (accident triggered by bad luck/terrorism/act of war...). Various unpleasant events since the 70's showed that the then dreamed "very very low accident rate" nuclear was a mere wish.

Add adverse conditions created by powerful nations/institutions trying to avoid nuclear weapons proliferation.

Nuclear used to be the only way to obtain low-carbon electricity, and this may counterbalance some of those ordeals. But no, as the new kid in town, industrial renewables, is incredibly good and quickly progressing https://ourworldindata.org/grapher/nuclear-renewables-electr...

Innovative ways are far away. SMRs, for example, are touted up and NuScale was quite dynamic but then... their first project is now down. https://www.reuters.com/business/energy/nuscale-power-uamps-...

Closing the 'fuel' cycle (breeder reactors) would solve many (not all) those curses, however after decades and billions poured by many nations into research and prototypes it is not industrial ( https://en.wikipedia.org/wiki/Breeder_reactor#Development_an... )

Nowadays nuclear is to energy what the mainframe is to IT.