Manufacturers make and sell different classes of drive.
Those cheap USB drives at OfficeWorks and JB are not rated to run 24x7. They are designed to be 'archive' drives - put data on them and then leave it. And sometimes they aren't even native SATA drives inside, they have USB on the drive itself (passed through to case), which means if the case fails, the drive fails.
I only ever recommend good quality drives (usually the WD Reds or Seagate SVs) in high quality enclosures. That way if the enclosure does fail, the drive is saved, and they are rated to run 24x7 etc. Obviously data should be backed up, but I also worry about those cheap $15 cases - I've had them kill HDDs before and corrupt data before (through random disconnects). Worth paying a bit more for the enclosure I reckon, especially if you're putting a relatively expensive drive in them.
This is my current enclosure of choice (no affiliation with the link): https://www.epowermac.com.au/products/sarotech-hardbox-esata-fw800-usb-3-0
I love that it has a built in kettle plug power supply rather than needing the line lump or awkward adapter that doesn't fit a UPS or power strip.
For slightly more budget conscious and assuming you don't need Firewire or eSATA, this one is my alternate suggestion: https://www.scorptec.com.au/product/Hard-Drives-&-SSDs/Enclosures/60383-NST-386S3-BK