In very large and complicated fields, you'll often have a minefield of conflicting patent claims, much of which are minor improvement patents. These often coalesce into patent pools, assuming all participants in the pool are interested in playing ball. (Looking at you, H.265.) You don't see certain players looking to invalidate patents on the basis of not having been paid for the right to improve their invention, because such a right doesn't really exist.
It's generally not good for your business plan to include the ability for your direct competitors to shut you down if you become too competitive.
I don't follow your thesis. Are you claiming there's someone out there who is being blocked by the eink manufacturer with a threat of a patent?
The comparison earlier to FDM 3D printing is spot on. The entire industry stagnated for over a decade under Stratiasys, who had no interest in pursuing the consumer market. It was only after the patents expired that the explosion of affordable printers and innovation in filaments happened.