Google photos on ios is literally a hostage situation. Remove key functionalities like copying an image or editing an image unless you give them full unrestricted access to your entire photo library. (The holy grail of surveillance capitalism data). Data extortion masquerading as a service.
People don't know. Researching good image backup/sharing options is beyond most normies. Privacy invasion isn't even a known problem for them to care about.
My parents certainly won't be able to comprehend this. My brothers are tech savvy, and it's taken years for them to come onboard with self hosting since I've started advocating it (one still can't because his wife finds it difficult to move away from Google photos).
And that also works and is used by people on Android. But you said the "standard app" is a good alternative on iOS but do people on Android use it, so you can actually benefit from shared albums and such?