Determining if someone can actually learn certain things on the job is pretty difficult in an interview setting, it’s way easier to just do a technical interview.
The alternative is probably something like a probationary period where you work with no guarantee of continuing but that’s a massive waste of time for everyone involved and not fair to the candidate.
In my experience, if you go with the candidate that seems the most well rounded, you’ll have the most success. Going with someone that’s a technical genius with no people skills makes it harder to fit them in a spot where they’ll shine - at least in a smaller company