A serious question since I was just in the bath ... How did they cut their toenails 500 years ago? Or their hair for that matter? I think there were no toenail clippers up until about 1910 or so ... Scissors were around but not well designed, far too crude to get that little toe?
my guess is that most people worked hard enough with their hands and feet that the nails broke off/were worn down before it became a problem. Or they could wear them down on rocks. I'm sure there are millions of people throughout the world that have never seen toe nail clippers or scissors right now.
A sharp knife works well enough, I often trim my nails with my box cutter, because I don't really notice my nails till I'm at work, when they're catching on boxes and stuff. That shit hurts, so I trim them down when it happens, because it reminds me. Never done it for my toenails but I'd assume it'd work just as well. Just gotta be careful not to slip.
The early Romans shaved with crude straight razors after learning men could grab their beards and slit their throats in battle.