In many research-intensive products go-to-market costs are bigger than the cost of actual invention. You buy a pharma startup for a few million for their patents, then spend tens of millions on certification, trials and manufacturing pipelines. Your competitors would spend most of that too on the same markets. Also, true inventions are rare. A lot of stuff that is being patented is just effort spent, that a lot of people could reproduce (and routinely reproduce, then hit the patent and spend more time to find a workaround).