Did this guy get radicalised against fossil fuel alternatives because he listened to one too many fossil shills or is he himself one of the fossil shills? I guess at this stage it doesn't really matter.

There's an old story that capital and materials are cheap when nobody is interesting in building things but they go up dramatically when people are.

Back in the 1970s, inflation and high interest rates were a big reason why nuclear power plant costs spiraled out of control. They haven't started building a NuScale yet but the cost of very basic inputs has been increasing dramatically

https://www.cato.org/blog/cost-escalation-delays-small-modul...

Other energy systems need the same inputs as steel, so it's reasonable to expect that cost escalations will affect all sorts of energy systems.