I need my phone to log into my banks website. (Fortunately my current bank doesn't cause problems with custom FW but others do)
It's basically not possible for me to do my taxes without a phone app that requires SafetyNet. (I don't need to do my taxes, my employer files taxes, but I'm probably missing out on some tax returns)
The public transport ticket app randomly stopped working on LineageOS after an app update. (I don't need to buy tickets on the phone but it's a lot more convenient)
This stuff is already really difficult for me to navigate but ideally FOSS mobile OSs are for everyone and not just nerds. I could never in good conscience wish that onto a person that isn't as tech interested.