Comment by WorldMaker

Some of it is convergent evolution at work. 60s/70s/80s specialized formats as much predated modern database designs and data structures as coexisted with them. SQLite is the culmination of decades of database design. Some of that was influenced by those specialized formats of previous decades that SQLite could now in theory replace.

(Which is to say a lot of the specialized formats didn't exist just because of compute and storage resource limitations, but also because training/research/standards work came later. Plus complications like software patents. ZIP files have been around since the 1990s but ZIP only became a common general use container format for "everything" almost exactly 14 years later when patents finally expired.)