I'm reading the Diamond article you liked and I cannot understand for the lift of me what you wanted? The Brittanica article seems substantially poorer. Note also that a key feature of Wikipedia is the hyperlinks! If you don't know what a "crystalline structure" is, or you want to know more about "hardness", you're welcome to click the links and dive further!

The wikipedia is more information dense, but that's not always what I want in a general purpose reference. Also hyperlinks are good if you want to read the article. But I don't want to have to click through hyperlinks, and thereby lose focus. Sometimes I just want to know just enough to complete the context in which some thing was mentioned. In the opening sentence there's a whole phrase "solid form of the element carbon" hyperlinked - to what is not immediately clear - but curiosity peaks the mind and I see that it's to an article on carbon allotropes. Later on it says it's "metastable" so I need to know what that means, but it just links to an article that's equally obstruse and so I have to go on an endless rabbit hole of hyperlinks. Britannica usually explains briefly in parentheses what some piece of jargon means.

Let me point out, that for me personally, for many years, hyperlinks in Wikipedia were the worst feature. I hated that! Anytime I started looking for something, I would start following links ad infinitum. Was extremely distracting. Instead of a little inline definition, for everything is a link. There is a good balance between linking to the definition of each word, and just inlining the definition.

Anyway, at some I disciplined myself to not follow the links. But sometimes the definition really needs following them.