Not all functions require fixed-width. E.g, I had the page open for a very little bit and it reached a point where the net worth was around $32,674. The function of showing numbers in this comment does not require fixed width. Aesthetics and readability are more important. Both of those are subjective traits. You can optimise for a particular group's aesthetic tastes, or a particular group's readability. Whether or not that requires fixed-width or not is not something I'm able to comment on, however.