It’s not that auth is unsolved in other languages/frameworks, but it’s often way too complex or configuration-heavy. If adding passkey support to my app is going to take 2 hours, that’s two hours I’m spending away from building my core product. For smaller projects, that’s not time that I could afford.

For example, if I want to add passkeys to my .NET CORE app, this is the guide Microsoft provides:

https://learn.microsoft.com/en-us/aspnet/core/security/authe...

Contrast that to better-auth (which is 7 lines of code total in server changes, and virtually no change to client API usage):

https://www.better-auth.com/docs/plugins/passkey

For some projects, the flexibility of other solutions might be needed. But for ease-of-use and development speed, better-auth has been a clear winner for me.