Game changer for us was using those plastic bread bag twist ties. Wrap each strap into a loop and secure it with a twist tie before you bundle them together. They stay neat and you just snip or untwist one when you need it.
That's smart for short term, but I've had those plastic ties snap after a few months in the junk drawer. The rubber bands from broccoli or celery bunches last way longer for the same job. They stretch so you can bundle the loops super tight without cutting into the strap material.
My hiking pack from 2018 still has the original plastic ties holding the straps. They haven't snapped yet, so maybe we're overthinking this. Daniel_green42's bread bag method sounds like a lot of work for something that just sits in a closet. Do our backpack straps really need this much babying? I just chuck mine in a bin and they survive every trip.