OTR still has static identities, with DH used to ratchet the ephemeral keys. The comparison would be more like Signal ditching Safety Numbers and Registration Lock for hourly SMS verification of new independent keys with no successor signing.

There's a fundamental divide in what certificates mean: modern CAs view WebPKI as a fancy vantage point check--cryptographic session tickets that attest to the the actual root of trust, usually DNS. Short-lived certs (down to 10 minutes in Sigstore, 6 days trialed by LetsEncrypt) make perfect sense to them.

But DNS challenges are perfectly forgeable by whoever controls the DNS. This reduces authentication to "the CA says so" for 99% of users not running a private CA alongside the public one.

Transparency logs become impenetrable to human review, and even if you do monitor your log (most don't), you need a credible out-of-band identity to raise the alarm if compromised. The entire system becomes a heavier Convergence/DANE-like vantage point check, assuming log operators actually reverify the DNS challenges (I don't think one-time LetsEncrypt challenges are deterministic).

I think certificates should represent long-term cryptographic identity, unforgeable by your CA and registrar after issuance. The CA could issue a one-time attestation that my private root cert belongs to my domain, and when it changes, alert to the change of ownership.

Yes, that's the whole point..

Er, I mean, its totally for security guys!