I think geothermal is a scam?

I remember reading somewhere that geothermic heat basically doesn’t replenish (or only does so at geological timescales), and by extracting heat from underground we’re basically depleting the underground heat reservoir, leading to shrinkage of the ground and therefore possible cracks in buildings.

TL;DR: It’s not truly renewable, but rather renewable only on geological timescales (similar to fossil fuels).

Was it not here yet? What changed?

Edit: Ah. Better drilling techniques, ironically, pioneered by the fossil fuel industry!

Latimer and his colleagues improved on traditional geothermal techniques in several ways. But the biggest was this: They utilized horizontal drilling, boring about 10,000 feet down and then 5,000 feet to the side with each well. The technology has been around for decades, but it’s gotten a lot less expensive since the mid-2000s due to widespread adoption by oil and gas companies.

Nice that this drilling technology can be used in green energy applications too.