I have a suspicion that the majority of code is rather mundane. After all the community did create the term CRUD to describe typical corporate work.

The number of people I’ve seen use the term CRUD while simultaneously not knowing what isolation levels are is deeply concerning. Unsurprisingly, every crud job I’ve worked has had many race conditions / data consistency issues.

You could basically categorize all programming as CRUD (you’re just reading and updating some bits).

In my experience your suspicion is well-founded. Most commercial software is written to solve some business problem or another, and the novelty mainly comes from the specifics of the domain rather than the software itself, as most businesses have broadly the same problems.

The average non-software business likely doesn't need to innovate in the software space but rather automate as much as possible so they can innovate elsewhere.

CRUD has a different origin, but it became synonymous with a certain style of... uninspired web development