CTA repetition – Is having CTA in nav, hero, and footer overkill?

This is a pretty common design.

Theres a CTA in the hero and nav with the same CTA and when you scroll to the bottom theres also another CTA that says the same thing. It feels a bit repetitive to me, but then again, I see it every where.

Are there any studies or research regarding the usability and conversion of this design? What are your thoughts on this?