I'm sorry; but have you ever actually used a database before? A database supports FAR more than "only CRUD". Some really simple examples are CTEs, SELECT ... INTO (or INSERT ... SELECT for some dialects), triggers, views, etc.
CTE's are extensions to try an regain some of what was lost when adopting a model loosely based on Codd's declarative relational algebra, specifically the lack of transitive closure, the rest mostly fit into the CRUD world.
It is a bit circular, CRUD's elements create, read, update, and delete were chosen to represent the core features of a persistence layer.
Have you completely missed the context of this thread? We're talking about the transaction log aka CDC. This consists purely of CRUD operations because that's all the database understands. Maybe read the books cited?
