What would you use very strong thread for?

Whipped and lashed things, and with the waxed kind I then let it sit in the sun and rub it down so the wax merges. I've used it for sewing, and for fishing. There have been a fuller list. It isn't as good as, say 20-30 test braided spectra fishline, but when I can put a hundred yards of cord in the watch pocket of a pair of jeans for under two bucks... Yeah, that's something worth experimenting with.