It’s a command that pulls a whole bunch of useful system information and sticks it on one page.
Really, the biggest use of it is for showing other people your system- especially showing off. It’s a staple of “look at my system” brag posts.
But to be generous, there are (small) legit use cases for it. If you manage a lot of machines, and you plausibly don’t know the basic system information for whatever you happen to be working on in this instant, it’s a program that will give you most of what you could want to know in a single command. Yes, 100% of the information could be retrieved just as easily using other standard commands, but having it in a single short command, outputting to a single overview page, formatted to be easily readable at a glance, is no bad thing.