Of course they do. It's just that I've done a fair amount of business by looking people in the eye. I've also worked at a 300 person software agency where that way of doing business was the norm. Sure, there was some paperwork, but it wasn't all-encompassing.
Indeed the entire London financial centre works with verbal contracts, at least where not switched to electronic, so the foreign exchange market etc.
Note the difference between a repeated game of many oral contracts over time, vs a one-off even that will never be repeated (founding a massively successful company)
Did that paperwork not describe the work to be done and the payment to be made in exchange?