I never sell old drives, as for me they are not worth the trouble posting an advertisement. I often just store them for 'just in case that'.
I don't erase them either, because it simply takes too much time. I just write a note on it what's on it for possible future use.
But at the time I decide to clean my storage room, they are old, often very old and their capacity not anymore usable. Example: SSD drive 128 GByte, used in a PC from 2013 until 2020. Not worth the trouble selling it. Could erase it, but that demands to put the drive into a working PC and connect it to the motherboard. Why would I do that, if I just can crush the PCB in a vice? I am sure it is not paranoid do that, because I know where they are disassembled often if recycled and I don't trust those places! Better safe then sorry.