[lovelearning]

I think they're useful for targeting search intentions and monetizing through SEO, ads, affiliate links.

People are unlikely to visit "programming.io" and then search something specific, but if it becomes popular for a particular type of content or tone or niche purely through organic search, people will include an easy-to-remember domain in the search query. Remembering "programming.io <query>" is easier than "johndoereactjsdev.blogger.com <query>".

It's not uncommon either. Just run a random tech search and notice how many hits are under generic "tec*" domains that publish how-to articles on multiple topics.