You know what's funny? Every time I have to use ls, I'm so used to seeing the colours that I have so much trouble finding anything. Which column in the permissions is group-read? I can just scan for the green one. Which file in the listing am I supposed to be looking at? I just look for the one with the yellow underline. Colours have familiarity to me in a way that letters and words do not -- if I expect to see green and instead see grey, I'll notice it faster than if I expected to see "r" and instead see "-".
Of course, not everyone feels this way. Colour terminals are not a new invention, and if the "colour in everything" crowd was larger, someone would have made exa sooner.
That said, I don't want to go too overboard with the colours. Here's an example: when exa was in its infancy I had the bright idea to highlight the root user in red, in the same way that it highlights your current user in yellow, because, I don't know, root is "dangerous" or something. I ended up seeing so many red usernames that I stopped seeing it as "dangerous, beware" and started seeing it as "just another file" -- which completely defeated the point! Now, red is a lot more scarce (just +w permission and inodes. probably some file types. not many)