Deleting old branches is something that really helps with sanity but almost never gets done. It really should be a formalized process. But then the formalized process in many cases isn't done. I've lost count of the number of times we've come to the awareness, multiple times, that we need to do <thing-that-prevents-wasting-a-whole-day-to-dealing-with-git> and having it never get done again until it bites us again. Oh well. At least we're still getting paid.