AWS is heavily used worldwide, not just in the US. The same goes for the big AI companies.

Timeframe is accounted for if you look at levelized cost per kWh. The levelized cost of natural gas is 5 to 11 cents/kWh. In the sunniest spots, the levelized cost of solar with enough battery storage to provide 24/7 power is about the same, if you want >90% reliability. The usual four hours of storage is only enough to account for the "duck curve" during the day.

https://www.pv-tech.org/solar-pv-and-storage-cost-declines-d...

https://ember-energy.org/latest-insights/solar-electricity-e...

Solar and batteries keep getting cheaper so hopefully they will be clear winners soon, at least in sunny areas.