Well, once you know that PowerShell uses the verb "Get" for fetching data, and the noun "Content" for file contents then those are reusable bits of knowledge that slot together with other verbs and nouns. It's easy to hold in your head and build your knowledge over time, and better yet, the third-party add-ons obey the common conventions, so you can experiment with confidence.
When you learn the *NIX command-line from scratch, everything is special cases, so the whole experience is peering at man pages and slowly rote-learning commands and options. The only commonality is that if you try to guess, you'll probably be wrong. My patience with the philosophy of independent tools hit breaking point a while ago, when I had to start learning the different CLI tools from rival cloud providers - so much to learn, and no consistency at all.