If you had constructed a new technology that is an improvement of a patented technology, the original owner doesn't gain ownership over your improvement. They only have the right to prohibit use of the original technology. If you patent the improvement, then anyone who wants to use it would have to license both your patent and the base patent's inventions. There isn't a concept of "derivative works" (like in copyright law) where if you didn't license the base patent, you lose ownership over the improvement. If you had failed to patent the improvement, then yes, the patent holder could conceivably use your improvement without paying you, but that's a different scenario.

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.

The original owner can just refuse to license their patients however, leaving the improvements useless.

They can charge you so much for the license that you'll never be competitive even if your technology is a great improvement on the process.

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.

> There is no point in even trying to improve the technology right now because the patent holder would just take it anyway

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?

You would have to be insane to put yourself in the position to start with, so as long as the threat of the patent looms over the industry nobody is going to bother.

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.