[VLM]

I would make a microscopic improvement on your otherwise good comment by pointing out "databases" are big and interconnected, but not hard at all.

Hard is stuff like some very obscure sort algorithm which is mysterious but once you figure it out, you can apply the sort.

Big and interconnected is what RDBMS is where knowing only one or a couple topics in isolation makes the whole thing appear useless... if you all you know about is normalization, or the idea of foreign keys, or the idea of indexes, or the idea of transactions, individually it all seems like a waste of time lets just use CSV files. But once you know a critical mass of the (simple) parts, its becomes a valuable tool.

If sorts were like RDBMS then once you understood the quicksort you'd still be inherently unable to ever apply a quicksort unless you also knew the radix sort. But they're not like that.