The more code changes, the easier it is to change

It would also be worth stating that frequent code changes should be applied with regards to mid/long-term maintainability, otherwise, the pile of legacy code will stack up faster, and the wall would be hit earlier.

Also, not the same people are usually working on a given piece of the codebase for a long time, but people come and go, with different knowledge and backgrounds, so if there are no common guidelines and/or practices within the team/company, it could lead to chaotic codebases regardless of the code changes' frequency.

I believe this. But is there any research demonstrating this? I'd love to bookmark some data.