Haven’t done anything with Apple sign in, but I worked with a lot of other providers before. If you have multiple options, users might forget what service they used. This becomes an even bigger problem if the paid for a service with a different provider and can’t find their purchase. If you do use something like this, only having one provider (only Apple) makes things less confusing.
However your solution... doesn't work. Apple requires apps that support social app to have sign in with apple. Google has similar requirements (because your app better be multi-platform in this day in age). Facebook is way popular. So that's three right there.