But then are doing the bubbling manually and, on top of that, you pollute the return type of all the methods along the way. Suddenly, callers of such a function

But then are doing the bubbling manually and, on top of that, you pollute the return type of all the methods along the way. Suddenly, callers of such a function that just needed an Int now have to deal with an Either<Error, Int> and all the boiler plate that comes with it. Exceptions fix that by not bothering any of these users because the return type of the methods in-between is not affected.