I guarantee Google still makes money from those users. Google Photos adds value to the Google ecosystem, attracting more users and more paying users. The more history you have stored with Google, the harder it is to move. It also promotes other Google services users do pay for.

I'd guess this is a move by someone in middle management to increase revenues for their product, without seeing the bigger picture, where this move probably has negative shareholder value.

This doesn't exist. But you can schedule a year of e.g. 2 monthly incremental takeouts at takeout.google.com and stop-limit your dataloss scenario to a window.

btw: I think it should exist. I think google should clarify its 'we terminated you' process to include the takeout function for export of the data they currently hold hostage.

PhotoSync (https://www.photosync-app.com/home.html) lets you do a good-old-fashioned dump to a NAS.

I use Syncthing to copy from my phone to my NAS to backup the true original files.