> _capitalization_ is one of those "arbitrary rules"
If you're going to qualify capitalization as an arbitrary rule, then it wouldn't matter if it's all lowercase or all uppercase. It's not a whim of scholars, it improves readability, it emphasizes, it carries meaning.
All uppercase looks loud today, but early computers were also all uppercase and it was normal. All lowercase looks bland and sloppy, only a few steps removed from "what u doing lol?" texting shorthand.