The thing I hate most is when some creates the "new way of doing things". Then fails to convert most of the existing code which is "doing things the old way" even when it's clear that it is the same thing.
If you treat the new way as an experiment, and only gradually convert the rest of the code, you're in for a smoother ride.
It's totally fine to try out an experiment in a branch and deploy to QA but don't deploy it to prod until you're sure.
This comes from a lack of discipline in the org, not from the parent's (IMO) correct guidance that an org should undertake architectural changes with pilots in isolated parts of the code base.