As others have mentionned downloading the .deb and running it will also work, but I feel nobody gave your a tldr of why you may want to follow those instructions instead, so here it is:
Those instructions configure your package manager (apt) with a new repository for this application.
The upside to that is that anytime you will look for updates, this app will also get updated.
It’s a bit more work up front, but it can pay off when you have dozens of app updating as part of normal system operations.
Imagine a world where windows updates would also update all your software, that’s what this is.
I agree with the sentiment of your post, but I think the examples are a bit too far fetched:
I’d wager most people use a computer/phone on a daily basis, which is why having a basic understanding of it seems like knowledge we should all have.
Inversely, most people don’t need even have a turbo in their car and many don’t even have a car, so any knowledge relating to that is probably useless for them.
That being said, even if someone is less knowledgeable in a field, respect should always be the baseline, as you illustrate, they’re probably skilled in something else!
I’m saying that as an IT person that’s aware that I’m making money mostly because people don’t bother to learn all this, so in the end I don’t mind that much.