If you care about it, then buy Android phones that will support sideloading. Financially reward companies that are doing what you want.

Which Android phones? If I understand correctly this will be a requirement for certification, so any devices that do not enforce it will not pass integrity checks. Goodbye banking apps, etc.

Chinese phones, ones with GrapheneOS, new ones created to fulfill the market demand Google is creating.

>will not pass integrity checks

Those apps can add support for other integrity APIs. Operating system owners can fund this work to help their operating system gain marketshare.

This affects all Android devices with Google Services.