Should I apply to schools I am not sure I would attend?
The reason this is the “most common advice” is that it is the correct, logical, and ethical thing to do. You’re overthinking things. Asking for letters of recommendation does not imply any commitment on your part to attend a specific school, or to pursue a degree at all. The assumption the professors are making is that you are considering doing such a thing, among the various opportunities that may be available to you - nothing more.
Good luck with your applications!