Why do you want this when there are wildcard certificates? That's how the hyperscalers do it as well. Amazon doesn't have a separate certificate for each s3 bucket, it's all under a wildcard certificate.

Amazon did this the absolute worst way - all customers share the same flat namespace for S3 buckets which limits the names available and also makes the bucket names discoverable. Did it a bit more sanely and securely at Cloudflare where it was namespaced to the customer account, but that required registering a wildcard certificate per customer if I recall correctly.

The only consideration I can think is public wildcard certificates don't allow wildcard nesting so e.g. a cert for *.example.com doesn't offer a way for the operator of example.com to host a.b.example.com. I'm not sure how big of a problem that's really supposed to be though.