Much of the time in my experience, a tech interview is sheepishly excused by the interviewer as an antiquated ritual insisted upon by higher ups beholden to investors who have no idea how to evaluate talent. Like math tests, instead of evoking creative solution, they see if you hit the same target that they already know.
The qualities and aims in the interviewer that you put forth would be great to find in the field. Often, the interviewer is a staffer who is stuck doing the interview is rotated out of a tech team, and might not really have the interview on their mind, or is constantly comparing the prospect to the 6 others interviewed in the past week.
I also object to the laundry list of resume requirements, often enough full of inconsistencies, and in the rapidly changing world of computing buzzwords and discoveries, irrelevancy.
Among the qualities that should be sought should be curiosity, the ability to learn new programming metaphors, the ability to research, evaluate, and improve existing solutions, and the ability to push back at misguided business logic requests.
New languages are easy. It’s how they interface with existing packages - and what those packages do - that matters. New packages and APIs pop up with every release, and worse, deprecate APIs alarmingly often as the philosophy of what they do changes.
Tech interviews should endeavor to see how the candidate deals with those issues.