I'm a senior frontend engineer and I would absolute use this question in my future interviews.

These are really important details to know to become an effective frontend engineer.

Personally I have encountered several bugs related to wrong or incomplete meta tags on html (css units don't work properly if you fail to declare correct doctype).

Not knowing them will either slow you down in solving a problem (SEO, performance, browser compatibility), or introduce a variety of bugs sooner or later.