So an example of an application of Hick's Law is when you have a huge country list dropdown. Per Hick's Law we know that presenting users with many choices is bad because it'll take them forever to make their pick. But if there's going to be a small number of options that the vast majority of users will choose, such as with countries it might be the US and a few EU countries, you can improve this by putting those countries first and presenting an alphabetically sorted list of the rest after them.
You can see how this doesn't just boil down to "make it simpler". And many of your summaries similarly miss the point.
I do admit that the website doesn't elaborate on the concepts very much. For example, if I hadn't known about Hick's law beforehand, I might have arrived at the same conclusion as you. But they do link further reading which seems to do the job of explaining the laws in detail. So I think the website is a nice reference if you go the extra mile and look at the links.