the very idea of certification is that someone is there to stand behind the certificate and vouchsafe for it. if you have an authoritative source inserting your certificate in a blockchain, it solves the problem of instant verification.

Companies would consider this a great thing for hiring

why do we need certifications? Because people either claim what they are not OR hide what they are.

eventually experience is the only thing that matters. if blockchains are able to shed light on our experiences, then i am sure that certificates will disappear. Unless it is a certificate about our experience!!