If I'm glancing at some code on my phone, I can have it set to two space tabs to maximize the amount that fits on screen. If I'm on my desktop they're four spaces because my screen is huge and more visibly apparent indentation is valuable. Same editor, same data. If it's a shared codebase and someone else likes 8 space tabs, 6 space, or whatever they want (13 space? no kinkshaming here...).

To me that is a significant objective advantage of tabs, where the only advantage spaces seem to offer is that you can align text on multiple levels of indentation.