The massive difference being that they would scan photos on my device. Not on the cloud. On my local device. How is that people consider that better?
The important bit is that Google does not currently have any capability to scan stuff on my phone. This is good. It's my stuff. They have no right to look at my stuff.
Apple proposed to implement tech that could scan stuff on my device, with a promise that they'll only do it when I am uploading stuff. Wait a few years, and some pressure from Authorotarian Government/Corporate Overlords and now the promise is just a promise that they can be easily removed and we can scan all stuff to make sure you're not stealing "content"/spreading "propoganda".