Drug development seems to be the case where the patent system actually works and I wonder if that is due to having one patent per product? Elsewhere you get pat

Drug development seems to be the case where the patent system actually works and I wonder if that is due to having one patent per product? Elsewhere you get patent thickets and invention choked off by multiple ownership. Perhaps a useful reform would be to insure that no product is encumbered by more than one patent. This could be done by letting the most inventive patent covering a particular product be the trump patent. Minor patents would lose their nusiance value. Research incentives would be turned upside-down. Instead of doing cheap research to get a trivial patent and a seat at the bargining table to leech off real inventors, expensive research, aimed at major breakthroughs would be the only way to win.