This is very emotive language, which is fine, but there is no currently projected scenario where mass extinction is inevitable or even likely.

Great, but we don't have the transmission, storage or gas generation currently.

We are well on the way. In many parts of the world this is the majority energy mix already.

So we need to spend trillions to build a system that still produces enough CO2

This is untrue. It's roughly the same cost as replacing coal stations with new coal stations, which is roughly ten times cheaper than replacing them with nuclear. And it cuts energy production C02 production by about 70% which is easily enough to meet most targets to stabilise the climate.