I have a computer science degree, I've been coding for 20 years, and I've held (and kept) a CTO role at two mid-sized startup companies. Currently I'm considering looking for a job at a larger company (where I wouldn't be CTO but I'd be hopefully paid more) and these kind of questions make me think I need to almost go back to school before I can start interviewing.
When did it get to the point where we need to read thick books on programming interviews and spend hundreds of hours on HackerRank practicing algorithms to get a job where we probably won't use any of those day-to-day?
Edit:
For fun the other day I decided to code a linked-list from scratch in C and it took me a half-hour plus... and I have known that data structure for decades. I can't imagine doing a harder problem under the pressure of being an interview.