Exactly. We'd had discussions about building https://Userify.com (plug!) around SSH certificates, but elected to go with keys instead, because Userify delivers most of the good things around certificates without the jank and insecurity.

It's not that certificates themselves are insecure themselves, it's that the workflows (as the parent points out) are awful. We might still add some automation around that (and I think I saw some competitor tooling out there if you're committed to that path) but I personally feel like it's an answer to the wrong question.