The problem is that most normal people (HN is not normal - mostly for the better) don't even understand what sideloading is - let alone actually care.
How can we fix this?
(aside from making people care - apathy enables so many political problems in the current age, but it's such a huge problem that this definitely isn't going to be the impetus to fix it)
unlock. flash. spread the word. use the fork, Luke.
Without attestation, banking apps stop working and without a banking app, you are locked out of modern life in many ways.
This latest Google move makes it impossible to run an attested Android without the sideloading limitation. That means that you'll have to choose between GrapheneOS and using your banking app.
I'm sad to say that I've already had to make that choice :-(. I feel that I was coerced into it.