Wired discusses patent restriction here: https://www.wired.com/2016/05/get-ready-world-covered-electr...
Just look at the relevant patents still being filed by the company here (mostly trash): https://patents.justia.com/assignee/e-ink-holdings-inc
See patent suits across the globe - Germany: https://blog.the-ebook-reader.com/2015/03/02/german-court-fi...
Here is the position for their patent lawyer, who actively discusses their "offensive and defensive" actions around their patents: https://www.linkedin.com/in/brian-bean-0988645
Here are articles discussing the 115k yearly buy-in for their tech (https://www.epo.org/news-events/events/european-inventor/fin...). And note - if you're not large enough to discuss that with them, they usually won't even bother responding.
Wonder why 2016 saw a rapid increase in EPD devices? It's because they lost that 2015 case in the EU.
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So your whole argument boils down to - "they don't do the volume". Which is true but meaningless: Clearly there is demand for these devices, why is the volume not ramping up to match? And I'm saying "Patents and IP restrictions". What are you claiming?