If you're doing intensive activities, which Windows 11 might sometimes do in the background, or add to, your hard drive could be being accessed due to a need for swap memory, which is just taking a tiny chunk of your drive, and treating it like memory. It could also be that your computer has to pull new resources from its files, which would also access your hard drive frequently, given a big enough load. Perhaps you should look into your memory usage, and see if some of it's working incorrectly, or if you don't have enough for your standard use case.