Old cheap android devices nearly always have no available storage space, which makes it almost impossible to install a native app. Freeing up 1MB of space isn't enough to allow you to install a 1MB app - typically you need to free up 1GB or more before the store will function at all, and there's a good chance on old devices that won't be possible at all, due to the way updates consume space, and old devices have a lot of updates...

PWA's aren't the perfect solution here - on those same old devices, theres a good chance your user is running a 5+ year old browser engine, with a lot of bugs that are hard to even test against, considering how many combinations of screen size, phone, and browser software version there are.