This is true when fresh college grads are building stuff. Experienced engineers know how to build things much more efficiently.

Also people like to fantasize that their project, their API, their little corner of the codebase is special and requires special treatment. And that you simply cant copy the design of someone much more experienced who has already solved the problem 10 years ago. In fact many devs boast about how they solved (resolved) that complex problem.

In other domains - Professional engineers (non-swe) know that there is no shame in simply copying the design for a bridge that is still standing after all those years.