As an innocuous example of sharing data with pure bash and Arise, these people here have preserved the Trigedasleng dictionary, the fictional language from the science-fiction/young adult show The 100, after another fan site was taken down. They use a github repo as data backend, and Arise as a static-site generator for github pages. All their data are stored in lots of version controlled JSON files instead of a database. According to the authors, this democratizes the process of forking and adding data to the repository.
All this is speculative of course, but those domains you listed are vanity domains in lucrative markets. I call them vanity domains, because it can easily set you back 3-4 figures to get a domain like me.blog , let alone yourname.cars which is quite desirable if you sell cars. As with everything else, domain prices are simply subject to the laws of supply and demand.
Regarding .io , compared to average country code domains, such as .de for example, that tend to be quite modestly priced, .io has seen substantial increase in the past 5 or so years, transformed from a geeky exoticism to a symbol of AI-hype tech companies.
At least from my perspective.