With classic hard drives, at least, they have literal moving parts going on inside. So if you're not going to use them for a chunk of time, shutting them down will save them the wear-and-tear of "ongoing extra motion just to keep up background processes."

Probably also gives heat time to dissipate? I feel like modern engineering should handle that with fans and vents anyway, but it's gotta vary from one device to the next, at least.

But with solid-state drives, they aren't moving, the thing that wears them down is "writing new data to the disk, then erasing it, then writing something new in that space, then erasing it, then..."

And hibernating a computer means "taking the current state of the memory and saving it onto the drive, then loading it from there when you boot back up." So every time you do it, it writes a new extra-large file onto the drive. Which is more stressful than just leaving it running, and letting all that data stay in the memory continuously.

...although now that I think about it, this computer came with a tiny hard drive and the premise that you want to keep most of your files in the cloud when you're not using them. So a lot of my process, by design, goes "download files to work on, make edits in the local copy, delete local files after they're re-uploaded to free up space, download new files..."

Which, if your work involves a lot of large files, might wear down the drive fast enough that "not hibernating" isn't saving all that much by comparison. Like ordering lots of greasy high-calorie fast food, then taking care to only get the low-fat dressing :/