Many many different industries have jobs that require technical skills -- not tech as in technolgy -- and they get away just fine with managing to hire people. Nurses need to be able to nurse, a highly technical skillset; no one is having nurses give fake shots on test dummies during interviews. They use credentials and experience, and accept the risk that a hire might not pan out.
The fact that we want senior level developers to have to refresh/cram before interviews on how to implement graph search algs and hash tables just so they can pass some artificial whiteboarding section is a bit crazy. Their actual job experience over the past N years should be what counts.
Now, conversations about how one would solve technical problems of a sort actually faced on the job are totally on point, and really should be a part of any job interview in any field.
edit: Really, what we want as engineering types is for there to exist a way to gauge ability in a purely objective way. But there isn't one; it doesn't exist. Furthermore, you are building a team of people. IMO the focus should really be on fit and soft skills regardless. Make sure they meet a minimum bar of technical ability, then work to verify whether they'll be a productive, beneficial teammate.