Today I took out some of my old harddisks to clear out some shelf space in my office, and shoved them inside some external drive enclosures to see if any of them were still working. While a couple of them turns out to be completely dead, probably due to the rough handling when moving house, most of them still works. Nonetheless, being as old as 10 years old, these HDDs were effectively obsolete. So I chucked out the dead ones and put the working ones in a box to be transported back to my parent's home.
I used to keep a bunch of external hard drives to backup my projects, but nowadays cloud storage solutions are so affordable and so convenient, I hardly use them anymore. Currently I only keep 2 external 1TB drives for archival purposes.