Simulating a quantum system is a hard challenge and it's actually how Feynman proposed the quantum computing paradigm in the first place. It's basically the original motive.
I’ve seen lots of people dismissing this as if it isn’t impressive or important. I’ve watched one video where the author said in a deprecating manner “quantum computers are good for just two things: generating random numbers and simulating quantum systems”.
It’s like saying “the thing is good for just two things: making funny noises and producing infinite energy”.
(Also, generating random numbers is pretty useful, but I digress)