Indents should exclusively be a single tab per indent, not any number of spaces, and width should be handled by the IDE renderer, configurably, rather than baked into the code.
Only if a person's machine is set to a tab size of four spaces. By this logic, we would need eight spaces for the people with a larger tab size of eight on their machines so they could be 1:1. Minimizing horizontal space is ideal as not everyone has huge horizontal monitor space to work with. But, everyone has infinite vertical space with scrolling.
If your code takes up so much horizontal space with 4-space tabs, you're putting too much on one line or indenting too deep. 4-space tabs keeps your line length manageable.