These are good general tips applicable to other languages too. I strongly dislike when code returns errors as arbitrary strings rather than classes, as it makes errors extremely difficult to handle; one would presumably want to handle a http 502 diffrernetly to a 404, but if a programmer returns that in a string, I have to do some wonky regex instead of checking the type of error class (or pulling a property from an error class). I've commonly found JS and Go code particularly annoying as they tend to use strings, as the author mentioned.

An additional thing that is useful here would be a stack trace. So even when you catch, wrap & rethrow the error, you'll be able to see exactly where the error came from. The alternative is searching in the code for the string.

For the hate they seem to get, checked exceptions with error classes do give you a lot of stuff for free.