Rooftop solar and grid scale solar farms are two completely different things. Rooftop solar requires a custom install for every home. Solar farms can leverage economies of scale to drive costs lower and lower.

If you have to hire Some Guy to do anything to your entire roof, it'll cost you $30k. The panels are basically free these days, the labor required to install them is not.

Come to Europe. Our discount stores will sell you a kit for €200-€300. Not 20k-30k, 200-300.

That's on the small side of things, of course, but we also have PV-covered carports for about the same as a non-PV-covered carport: https://www.kaufland.de/product/512021383/

$30k for what? Your house? Prices vary massively depending on needs, and whether or not you want to reduce grid usage, time shift grid usage, or replace it entirely and go off-grid.

This article isn't about personal solar installations, in any event.

Solar panels cost less than $1/Watt. Then you need some brackets to hold them, some wiring, and likely an MPPT controller. The rest of that price is red tape specific to your locality.

They're so cheap that bars in Colombia had panels as their terasse awnings. Cheaper than cloth and makes power.

Vast majority of costs is in the installation and regulation, Australia home installation costs are a fraction of the cost of the USA and in Europe with plug in solar its a few hundred Euros for a couple panels and small inverter for a small setup

Cost per kW/mW is much lower at grid scale than home scale. For a home installation you are also paying for the roof mounting, running cabling through your house, inverter(s), and a transfer switch at minimum.

The cost of the panels themselves is becoming one of the cheaper parts of that project.

They're talking about grid scale solar, not home installations.

Home solar makes sense for the same type of homes that need to drill their own well. For everyone else, grid solar makes most economic sense.