That's the problem, it gives them a government enforced monopoly with no responsibility or obligation.
Patents should expire after a certain amount of profit is made from them, or come with some level of responsibility to use them for the public good.
Not only patents, that should also apply to copyright and the like. If the goal is really to push insensitive for innovation, creating uncapped profit will mechanically lead to undesirable situation (as per the stated goal) where an oligarchy will relentlessly take the lion’s share and let next to nothing for the rest of their late competitors.
Developing new drugs is a multi-billion dollar gamble. Between FDA approvals and research that doesn't go anywhere, drug making is a really losing game unless you make a metric ton of money.