I am not arguing against tabs. I actually find them a lot cleaner than spaces. But the default definition of a tab has it being eight spaces long, regardless of operating system.
It’s just that “tab = 4 spaces” is either the default in a number of IDEs, and in those which it isn’t, almost everyone changes it to that anyhow.
And yet, that is its default definition regardless of operating system.
That’s also why almost every IDE out there has tabs auto-set to 4 spaces, and/or gives the user to change it away from 8 spaces.