Beyond Selidor

I've heard horror stories similar to yours from people who booked accommodation via aggregators/price comparison websites, and for this reason I never do so, because, as you experienced, it becomes no one's responsibility if something goes wrong. (Same with flights — if the flight is cancelled and you've booked through an aggregator, you don't get put on the next flight or refunded, you just lose the money.) Those sites can be useful as search engines, and I sometimes use them in that way, then go to book directly from the hotel/airline etc — as you say, any money saved is not worth the potential hassle later on.

That trip to Japan with your friend sounds absolutely infuriating. I guess at least you were vindicated when it came to that ryokan, but in the worst possible way! I've only ever travelled with alone, with family or with my husband (other than a slim handful of times for work trips with colleagues to and from conferences/training etc), but I know so many people who have massively fallen out with friends after the experience of travelling with them. It seems to reveal something about the friend's personality or your friendship that isn't visible in everyday life, and I'm sorry you had to experience that.