My guess would be turning off is only turning off from you seeing them. Apple/Google still probably get the notificagion information, they just dony display it to you because you have settings to say not to. Specific apps woukd have to not implement notification or use their own delivery system.
😭
I know. Having a hard time trying to figure it all out. There have been warnings of this for years though. Notifications pass to apple and google first before you getting them. This is old news. Sketchy part is they were stopped from disclosing this to users. What else are they tracking they are legally not allowed to tell you about? Camera on all the time maybe? Secret mic recordings?