Arguably CTA isn't exactly an obscure acronym. It's multi-disciplinary - quite common in UI/UX design and marketing; and also decently common in any branched of software engineering that interact with these topics, like... web development.

There is absolutely no issue with using obscure abbreviations or acronyms as long as it is defined in the first use.

They think it makes them sound knowledgable.

I don't know why people refuse to look things up.