in all fairness, Java.util isn't some esoteric namespace. But the fact that you can do years of Java without touching core Java libraries (e.g. maybe you're highly reliant on DI, or have a proprietary library at work) does make it hard to properly gauge with.

I'd say it's a fine question if interviewers stopped treating their technical tests like trade secrets and just said "okay, interview is next week, make sure you know the some the basic built-in Java namespaces and yadda yadda". I can understand wanting to avoid googling, but consider the situations:

- someone truly out of their element won't pass, study or not

- someone who knows the stuff after a quick refresher is a perfectly functioning programmer, it's something all programmers do on the job.

- someone who truly knew nothing but could pass a test in a week is clearly a fast learner, the perfect candidate for many roles with changing demands

- and ofc the best interviewers aren't impacted. Simply more confident.

unless you truly need an expert/principle level engineer in a domain to solve problems (and let's be real: few companies do), I don't see many downsides to this approach.