> This can easily veer off in another direction, but I astounds me how many people shun the database and chose to reimplement innate features in procedural code outside of the database.

I've done this from time to time, and it's usually a question of the database clients are much easier to scale than the database. What can the clients do to reduce database i/o and cpu, because I can add more clients easily, but turning a database into a cluster is relatively more difficult, so database machines have to scale up instead.

Otoh, the limits of machine scaling are quite high these days. You can get a single socket epyc with 64 cores and 3TB of ram and tons of lanes of nvme.