Both tabs and spaces can in principle behave any way a user would want in editors, at least for whitespace at the start of a line. In particular, an editor could have (suitable ranges of) spaces behave like tabs, or vice versa. However, almost no editor provides the full range of desired behaviors for both. For example, one thing I don’t like about tabs is that cursoring over them makes the cursor jump, and not proceed at constant speed horizontally. An editor could in principle have an option to not do those jumps, but barely any editor has.