You need to look at the threat model. The threat model around eSNI public key substitution is a minor privacy invasion: Eve can see the hostnames you're conne

You need to look at the threat model. The threat model around eSNI public key substitution is a minor privacy invasion: Eve can see the hostnames you're connecting to. This isn't so bad because your DNS provider can already see the hostnames you're connecting to. Standards like DNS over TLS are being explored to make it harder for other parties to use this type of attack. The threat model around TLS public key substitution is basically full read/write control over your requests. This represents both a major privacy invasion and exposure of auth secrets like your bank account password. Your DNS provider doesn't already have access to those things. edit: You could deliver a cert this way, and authenticate the cert out of band e.g. through the CA system. This kind of approach is sound from a security standpoint, but there just isn't a lot of upside. There are fewer moving parts when you just deliver the cert the way we do now.