I think you’re missing the real-politik of rooftop installations. The person installing the panel has a few square meters of empty and unproductive space, over

I think you’re missing the real-politik of rooftop installations. The person installing the panel has a few square meters of empty and unproductive space, over which they have exclusive construction rights. And which is already connected to a grid, with capacity to absorb its production, physically close to the consumers of its output. That combination of factors is fairly rare in most of Europe & North America - especially when you’re looking for multiple contiguous kilometres of land for utility scale solar. There’s a lot of that type of land out in Texas and Australia, but there’s much less of it in the Scottish Highlands.