These are the pros I see for the Passkeys:
Most of our users will start by having just one Community
That makes Passkeys a good option.
Contacts can make Passkeys multi-community
If the user wants to move further with Seed Identity System, then the user downloads the app create a Contact a adds all the passkeys Proofs.
Passkeys do NOT make the hypermedia server a custodian
How Passkeys Work in Practice
When you sign up for a service, your device generates a passkey (private/public key pair).
The private key stays on your device, while the public key is sent to the service.
When logging in, the service sends a challenge to your device.
Your device uses the private key to sign the challenge and send the signed response back to the service.
The service verifies the response using the public key and grants access.
Passkeys can execute other action than login other sign up
We can use them to Sign Content on a Site.
These are the Cons a see:
Your Account Identity cannot be shared to the SHM App
It is stuck in the web
Your Account Identity cannot be used on multiple sites
Although maybe you can redirect to the site which has your identity? But this might have a very confusing UX