Are there any alternatives to the proprietary attestation of native mobile apps?
The EU's Digital Identity Wallet project has a lot of big icks.
Looking at the GitHub for the android Age Verification application feels like chewing rocks.

Like the proprietary attestation baked into a must-use form of identification is absolutely the wrong path...

And while we're at it, recall the rule of thumb: Age Verification either by deliberate or convenient naïveté is almost always a surveillance trojan horse.
Source:
https://github.com/eu-digital-identity-wallet/av-app-android-wallet-ui
Discussion
What about getting rid of the addiction to centralized fiat garbage websites and social media?
Parallel economy it is. Else you will need to comply with extortionists.
Yes, for example https://attestation.app/tutorial But it's not merely technical challenge, it's primarily organisational and legal challenge aka "who do you trust", with the customer base being million of regular users, not exclusively tech savvy nerds. But EU already has experience in trust services, originating specifically from the eIDAS directive since 2001.