that's interesting, for me interviews feel very similar to the work I do day-to-day, except I need to be on the whole time. If I have a work task like a tight deadline or urgent production issue that requires maximum effort for 5–8 hours then the feeling is very similar to how I feel after an interview. Maybe I am too close to the "fight-or-flight" mode during normal, lower-stakes work.
Interviews are high stress, emotionally draining, and, honestly, frequently rather degrading due to being talked down to. It's like having the fight or flight part of your brain firing on max for 5 hours. I agree that the only thing I really want to do at the end of such days is turn off.
That is wildly different from my day to day. After work, I'm still hyped to go to the gym, do some woodworking, program more, study. The world is an exciting place.
I've also found that if I succumb to the reddit infinite-scroll, a sense of numbness washes over me that takes awhile to shake free. I scroll like I'm seeking a high and nothing is doing it. Contrast that with, say, reading a book after work. Such a thing has never left me feeling the same empty feeling.