The device bound model also completely falls apart in the enterprise, fails to address shared devices and shift workers where employees share the same PC under the same OS profile, now you're back to needing good old fashioned SSO w/ physical MFA (Yubikey) to attest who the user is in addition to attesting the device itself.
Before synced passkeys, the actual standard is a unique key pair per device. The key pair on my phone shouldn't be synced to my laptop, my laptop should generate it's own key pair.