I think that's overkill, most of the time I just bubble errors up and I have very few cases where the error handling depends on the type of error. I guess it's because I don't use errors for things that are recoverable and try to fix them instead inside the given function. An example given here in the thread is reading from a file and if it doesn't work try a backup. Rather than having a function that reads from a file and returns a bunch of different errors I'd just make one with a list argument and then handle the I/O errors inside, and return an "unrecoverable" error otherwise.

For adding context, %w is good enough I find, though as I said I only very sparingly use errors.Is(...). Go isn't a language that's designed around rich error or exception types, and I don't think you should use it like that.