Easier to maintain how? I don't think I see it. Return values, at least as a mechanism, are strictly simpler; they do not introduce new control flow. They just

Easier to maintain how? I don't think I see it. Return values, at least as a mechanism, are strictly simpler; they do not introduce new control flow. They just use "return." Control always reverts to the caller. For an exception, you don't know whether it's the caller, the caller's caller, some generic exception handler, or what. It's no fun trying to track down all of the callers of A, some subset of which might not catch exception X, then track down the subset of those callers which catch X. Otherwise adding or removing error codes seems equivalent to adding or removing exceptions. Same with trying to decide which exceptions/errors to handle or bubble up.