I'd rather be stuck in an international country with only a phone than only a passport. Hell even when I've been in war zones if it's a choice between a working phone (sat phone for example) and a flak jacket, I'd go for the former.
You probably overestimate how easy it is to "just" get a replacement passport in a random location and get money wired to you.
As I wrote, I have personally had a broken phone and it was annoying--mostly because of the replacement cost--but had no problem getting home. I didn't just have my passport but didn't have a phone.
And/or ask the hotel. And if you're just casually backpacking, that probably means you know people (or are traveling with someone).
Frankly, probably reflects my computer background, but it sort of annoys me that my passport is more or less the one thing when traveling internationally that there is just no backup for beyond going to the embassy or consulate.
Domestically, you can have multiple forms of acceptable ID. One time I skipped that step on a last minute quick trip, I almost wasn't able to check into a hotel.
Not having a passport is a big issue that will take a lot of hassle to deal with. Probably a generational thing but losing my passport feels like a much bigger deal than my phone if I've taken reasonable precautions. In fact, my iPhone broke 4 or 5 years ago on a trip and I was fine.
Jesus Mouse once told me about how he'd smuggled LSD into Europe by cutting blotter paper up into little colored pieces of paper and gluing them all over his scepter as decoration, and nobody in customs or airport security was remotely suspicious about it.
