Windmills can be surprisingly expensive. https://www.eia.gov/analysis/studies/powerplants/capitalcost... is not up-to-date, but I think the windmill prices in it have changed a lot less than the solar prices; the 200 MW onshore project they price out there comes to US$1265/kW (US$1.27/W), of which something like 61% is the windmills themselves. Low-cost photovoltaic solar modules currently cost €0.055/W (US$0.065/W), lower by more than an order of magnitude https://www.solarserver.de/photovoltaik-preis-pv-modul-preis....

So, at equal cost, the alternative to a megawatt of windmills may not be a megawatt of solar panels, but 10 megawatts of solar panels. And that can compensate for their lower capacity factor.

I don't think people are building gas-powered data centers in the US. There's a data center crunch in the US because people aren't building them because they can't get the power because of the US's anti-renewable-energy policies.