I always ponder, after the years of experience - wouldn't you just leave the interview if it feels like torture?

I never ended up in a good place when it felt this way...

I'd say it's unprofessional to out & out leave the interview. Maybe for practical purposes it doesn't make a difference (though it can be a small world sometimes and you never know when something might come back to haunt you) but there's a certain amount of social norm & politeness involved, even if your own sentiment is "well they aren't respecting my time so why should I care?"

Also it can come down to just a bad recruiting/HR process and the place itself is perfectly fine to work for, and maybe that doesn't come through in the initial screening nonsense but you figure it out from the final round. Or you just end up not having a choice if the market is tight and you would end up wanting to take the job for the paycheck even if it's only 6-12 months while you find something better.

I guess depends on the context, I walked away from interviews where people were non-professional, rude or just plain wasting my time due to poor job description and completely different expectations. On the bright side, you save them time too.

Also I would say poor HR practices are correlated to the quality of the workplace but that's just a hunch that I follow. Not science backed.

I know this limits job opportunities, but a few years ago I started pre-screening the interview process. I ask specifically if the interview will be the whiteboard-type. If the answer is yes, I politely refuse the interview and tell them that I don't participate in whiteboard interviews. This is all done tactfully of course, but I refuse at this point in my career to be part of the tech hazing rituals. I have many other things I enjoy doing, rather than spending 6 months on Leetcode to ultimately make someone feel good about their previously worked out binary tree algorithm.

This has eliminated 90% of the stress involved in job searching, and I'm confident that I can get an offer at basically every interview I get into.

I'm not going to get a position at Amazon or a SF company, but after seeing what friends have gone through I have no interest anyway. I also make coastal money living in the Midwest, which was achieved by the exact method I outlined above.

Now if I was in a desperate situation I would probably be forced to go through with these whiteboard interviews, which would suck - you do what you have to do though. However, I wish more engineers would refuse whiteboard interviews. If more job seekers did this I feel like we could change the industry, but the whiteboard philosophy is so widespread that it's an uphill battle.