If they are similar, then it's easy enough to tell that also. E.g. 1 GB vs 995 MB.
I disagree; what's easier, spotting the biggest and smallest of these at a glance:
6,677,967
5,916,109
7,164,551
3,745,059,597
3,175
4,194,304
3,550,137
6.37M
5.64M
6.83M
3.49G
3.10k
4.00M
3.39M
But then you run into the case that the "32GB" SD image that you just dd'd won't copy to another card of the same nominal size, because it turns out that the destination card has reduced capacity due to 100KB of bad sectors, or something. Or your file went from 2100 bytes to 2081 bytes because your editor dropped all the \r characters. Or a network transfer ended a bit prematurely, chopping off the end of a file.
I'd consider these to be reasonable cases where the byte-exact filesize might be more useful than the readability-friendly version of the number.
On the other hand, yeah, there are a lot of cases where I just need a general idea of the filesize. "-h" display is wonderful for that.
Human readable units helps quite a bit with this, and I think that makes it a sane default. As long as you can specify you want to see bytes, and the sorting is done on the actual byte value, there's little lost because the majority of the time it will help rather than hurt.
Like I've said in these comments, I'm constantly surprised by which settings people change and which ones they don't, so differing opinions on exa's defaults is nothing new. exa shares my opinion of wanting to see thousand separators and byte suffixes by default; ls, on the other hand, has no opinion because with file sizes that small, it didn't really have to choose what the output should be like.
People have said that in scripts you'd want to just output the file size in bytes, and they're right, otherwise the numbers won't sort correctly. If you're writing a script, though, you're going to be taking more care than if you were just wanted to list some files. I've lost count of the number of times I've listed a directory, given up trying to count the digits of the file sizes, then re-ran the command with `ls -h`, but I've never written a script without thinking about what the output should be like.
I think your perception of filesizes is slightly skewed; "nine or more digits" means roughly >=100MB. Disk images, software, and videos would be in that range, but probably not the average MP3 (100MB of 320k MP3 is over 40 minutes), and I don't think I've ever handled a "word processing document" more than a few dozen MB --- and even that would already be many hundreds of pages.
Of the files sitting on my desktop at the moment, which is not necessarily representative nor typical but covers a wide range of types (pdf, mp3, zip, exe, jpg, mp4, ...), slightly more than 10% are 10MB or more (8 digits), ~15% have 7 digits (1-9MB), and the rest are below 1MB (<= 6 digits).
Even then, most of my documents are quite a bit smaller, as I have a tendency to write my documents in wordpad instead of office, and then save as rtf or txt.
How does 524404648 vs 5.24404648e8 look?
I would prefer to choose the base unit and see the decimals myself. Then I can quickly ascertain the difference.
Ah, but does "this tool" (whichever tool) mean GB or GiB when it says "GB"? As the prefixes get larger, the difference between powers-of-ten and powers-of-two prefixes gets significant.