The point is that using argv[0] to get the executable location can be quite fragile in practice and there are (OS-specific) alternatives that work much better for that goal.
It's not fragile at all. It's also cross platform without 18 ifdefs. It also doesn't necessarily or only tell you where the exe is, it tells you what was called. And maybe you want to know that. If sometimes you don't, so what? No one can say for anyone else that they do or don't need this bit of info, or should or shouldn't make assumptions based on it. The fitness for purpose is 100% context dependant. You have to be looking at some particular app and the rest of the environment it's running within before you can say "argv should not be consulted here, we should use this other interface instead" You can't say anything like that as a general case that automatically applies to everything.
