When I read an article like this that claims some architectural technique is broadly applicable, I don't think it is talking about hobby or just-for-learning applications. Certainly you can do whatever you want with those, but that's not very illuminating.
I'm not sure exactly what you have in mind for annotation apps for academia - things like zotero that run client side? If so, sure, there is a big world of client side software where a database is useful, and I think SQLite (or DuckDB) seems like a no brainer there.
I don't really agree about intranet apps, which are often even more critical to the people using them than an arbitrary consumer app. But I'll grant that for a company that spans a small number of time zones, you can at least have downtime windows outside work hours.
In any case, as I've said all over this thread, the only disagreement here is over what kinds of software is "most". And my intuition for "most" is based on my experience working on and using applications where a lot of effort is made to keep the thing running all the time while still evolving it. Maybe you're all right that "most" software isn't like that.
* Hobby apps designed for yourself and your friends.
* Hobby apps that you hope will become products but probably won't achieve traction.
* Apps where you're trying a new stack or framework.
* Annotation apps for academia.
Basically, every single app written by people who aren't doing internet facing web dev as their core engineering function.
Also intranet apps as other commenter mentioned.