Elon said the same thing about the US a decade ago.

"a fairly small corner of Nevada or Texas or Utah."

https://www.pcmag.com/news/elon-musk-running-us-on-solar-req...

See you next decade when we're saying the same thing and not doing it?

Musk was proposing about 1.2TW of solar capacity, the US installed about 250GW since then and is currently installing about 50GW a year and is projected to have 770GW by 2036 in a decades time.

So the US is probably over-delivering compared with many things Elon has proposed delivering himself.