I can kind of see your point regarding paid apps, but for free apps, you aren't really losing anything, besides maybe a few seconds of your time. If you don't like the authentication options the app offers, you can just uninstall it, and for 99% of the apps in the app store there's multiple alternatives that will offer a different set of options.
Unless I don’t have a google or fb account, in which case having an app listed in the store that I can’t use is hostile - and I bet it would be even more problematic if they elevated the rank of apps that supported Apple sign in over those that didn’t, even if it did reflect the value proposition for the user
