I disagree that it's unfair to expect apps to work without reading. Some apps, sure, but I think a taxi application ought to be usable without being able to read. Consider
1. The user is drunk, and can't understand meaning of the text.
2. The user is preoccupied with other tasks, and skips over the words.
3. The user is illiterate. Functional illiteracy is prevalent in the United States, and being unable to recognize the characters of one's own language continues in many countries, too
My company invests in ensuring many of their products are usable for the illiterate. I doubt it's the only company that does so.
Designing for the illiterate (or inebriated) is a nice goal, but designing for people to change their app into a language they cannot read, and then expecting it to all be easily usable, is not really a particularly great design goal. In that instance, a button could have a single word that 99.9% of people can read, but if you've changed it to Spanish it may render the button incomprehensible. I personally can't think of a single app I use that is completely usable without basic reading comprehension. I'd be curious about examples though (assuming reasonable complexity) because it'd be some potentially useful design that I'd be interested in seeing (and potentially using).
Adding to this, I'm curious how someone who cannot recognise the characters of their languages would use input fields, too? I don't think I know of many input fields which are particularly accessible if one doesn't recognise language characters without using speech recognition (which kind of sidesteps the issue).
As a (hypothetical) example, I'd imagine a pizza app to be pretty usable if I didn't speak the language (illiterate may be a bit much as I'd need to know my address):
Put in my postcode & choose my address; choose a pizza size & toppings from icons/photos.
Add credit card info into a standard looking form & that's it (or even, touch the fingerprint sensor when the fingerprint icon comes up)
I think the trouble isn't that you wouldn't know the Spanish for "OK" (or "pepperoni") but if the app lacks proper information hierarchy so you don't know what to do next.
If you're a foreigner you would probably be tripped by the post code/address. I certainly was when the petrol station asked for my post code in the US! (My card postcode does not fit the US format.)
Source: used to work for a direct Uber competitor (not in the US)
Drivers and platforms definitely don't want too intoxicated passengers. Reasonably drunk? Sure. Completely high/passed out/etc? Nope. It's just too much of a mess to handle. There is indeed a vomiting fee, but it's more used as a deterrent for the users: it does not cover the actual cleaning + lost rides on a busy Saturday night...
Bit of anecdata: sexual intercourse in the car is also not ok, and gets you banned. Yes, it happens. Drivers don't like it.
Ironically, part of the reason traditional taxi networks enjoyed their local monopolies in many cities was to compensate them for being considered part of public transport infrastructure, and forced to do the things that's not in their best interest (but is in the best interest of citizens).
1. The user is drunk, and can't understand meaning of the text.
2. The user is preoccupied with other tasks, and skips over the words.
3. The user is illiterate. Functional illiteracy is prevalent in the United States, and being unable to recognize the characters of one's own language continues in many countries, too
My company invests in ensuring many of their products are usable for the illiterate. I doubt it's the only company that does so.