That's basically what computers do.
The rule is a holdover from monospaced type like from a typewriter. On a computer with a decent font and renderer it will generally make the spacing a little larger than an in-between-words space, but not a ton like double spacing would. Basically typesetting is way more complicated than people realize but since we solved most of the problems computers have with it in like, the 70s, most people don't tend to realize it unless they have design training.
The follow up post is significantly more interesting to me, as it basically mirrors the comment section.
Put the foot down on your camera if you're going to leave it open. Not for any technical reason, it just looks better. Or don't I guess if you like it that way.