That's what most of tech hr is. The age discrimination that happens is a symptom of a much larger problem.
In general, I feel that a couple of technical questions relating to the fundamentals of the platform you're working with. Getting a feel for who they are and their track record for either delivering on the stack you are working with or in delivering on stacks with which they have little initial familiarity. Some people are particularly adept at learning entire stacks and delivering solutions in times that other developers are incapable of delivering on stacks with which they claim intimate familiarity. Others are amazing at delivering on a particular stack but have no clue how to achieve anything outside that stack.
I think the biggest issue is that interviewers have no idea how to abstract contextual information when removed from their development environment. They think that everyone needs to look and think like them... and if they don't, they're not a good fit.
As for hiring people they like that are technically inept vs. turning away candidates that are technically adept but awkward. I guess it comes down to social aptitude - being technically awesome is only half of the requirement. You've also gotta be likable or you're not getting hired.
In a way, this is a good thing for me. Getting a job isn't part of the equation. There is only one good reason for me to get better at my tech stack. It's because I want it to be easier for me to make good software.
I have decades of solid experience. Multiple 3-digit starred projects on Github. Typically the person that interviews me learns something from me in the interview process.
As I said, it is getting ridiculous. Possibly it is a way to age discriminate, not entirely sure.