We've finally had the paradigm shift that has sped up our shift out of plastics. It's similar to what happened with cast iron where I spent years applying steady pressure towards getting the rest of the family to stop reaching for Teflon pans. Overnight they fell in love with one particular pan and so we've finally finished with the Teflon. Apparently that size of around a quart hits the sweet spot of easy to work with but large enough to be worth filling in food storage.
I stumbled across three packs of kilner jars in this size for 8 dollars and brought home twelve. These were instantly filled. We raided my cases of freezer safe pint and a half jars to organize another shelf. When I went today to replace my canning jars they were on sale for 25% off every two cases or packs. So I have 4 more cases of freezer safe jars and 8 novelty spiral shaped jars in that size, that are easier to grip than a straight side would be.
If you've never seen them, Ball's freezer safe jars are a good alternative to plastic Tupperware in both the fridge and freezer. Yes, you can can in them also. My mother likes them as drinking cups because the measurements help her track fluids.
I think jars are soon to join socks and curtains on the list of things Casie can't control herself with.