Most apps downloaded from Aurora Store will not work on Google-free Android versions, because mainstream apps on the Google Play Store tend to require Google Play Services for even basic functionality.
I recently de-Googled both my phone and my wife's. Although we try to use FOSS apps as much as possible, there's still a handful of apps we've downloaded via Aurora, all have worked fine. Obviously YMMV but I don't think "most apps won't work" is true.
There is also microG which I think solves this issue. And I see it's even sponsored by /e/ Foundation https://microg.org/.