I remember in the early 2000s, I just got started with SQL and one of my reaction was "SQL is great, but why do we need a server? Why not use a simple library and files?" So I asked my coworkers if such a thing existed. And I had a lot of reactions along the lines of "it is stupid why do you want that? Just install a server on localhost" few people were convinced. It wasn't even a case of "nice idea, someone else should do it it", I think people just associated SQL with servers and by being new to it, I didn't have that preconceived idea.

A couple of years later sqlite was everywhere. It was exactly what I had in mind (but with nowhere enough skills to do it myself).