> I’ve never seen an ISP that doesn’t provide at least one publicly routable IP per customer, some, like mine, even provide additional ones for a few euros each.

There are a few ISP's in APNIC and LACNIC regions that hand out RFC1918 addresses to end users. I've seen a few NANOG posts of people trying to greenfield such setups in the US, too. Mostly in the RF/radio space.