I have edited all sorts of documents over the last 28 years. I couldn’t even begin to count how many pages that’d be. Just in the last year and a half that I’ve been in business full-time, I’ve edited at laest a thousand pages. One common correction I make is changing two spaces following a period to one space.
Despite what you might hear from one-space proponents, double spacing is actually centuries old and single spacing is the relative newcomer.
Up until at least the 1980s, double spacing was still taught in typing classes (which is why there are still so many people who abide by this practice), but even by then, the move to single spacing had been underway for several decades.
Today, single spacing is catching on. Some social media platforms even automatically replace double spaces with single spaces after you press the Post button, and HTML renders only one space no matter how many times you hit the space bar.
In fact, the big three style guides (AP, Chicago, and MLA) all promote single spacing. That’s why I follow the convention.
When it comes down to it, it’s personal preference. To be safe, check if your company has a style guide and if such a guide addresses this issue. If it does, follow its recommendation. Otherwise, it’s up to you.
As for me, I’ll still keep moving on with the single space.