That's a bit disingenuous and short-sighted view from people not knowing or understanding the industry, market, technology and manufacturing challenges. Sure, like any successful tech company, e-ink owns patents and controls a large part of the market more-or-less, but patents aren't the main reasons why the e-paper industry hasn't moved forward.
That's kind of like saying "ASML's and Cymer's patents are the reason the EUV lithography hasn't moved forward and why they have no competition."
No mate, that's not true. Just like EUV lithography, making e-ink tech displays, affordably, and at scale with good yields and healthy margins to keep the industry afloat, is hard, very hard, bordering on magic, which is the main reason they have no competition.
Turns out making minuscule pigment electrostatic particles that can quicky move around inside a fluid suspension and hold their position long enough at various ambient conditions, is a huge challenge, and manufacturing that at scale with very low defects and sustainable margins is even harder.
Nothing in their patents currently is holding back competition, but competition can't reach the scale and yields that would make enough profits to support a viable competitor consider even entering this field, versus OLED displays, as that's where thew real money is in display manufacturing right now and that's where the competition is heating up and where all the R&D money gets poured.
That's why there's been various alternatives to e-ink-like tech popping up from university research labs and being displayed at trade shows, but going from a research lab one-off prototype being shown at trade shows, to mass production at scale with good yields and profit margins, is the real challenge and is where e-ink has their secret sauce that nobody can successfully replicate.
Similarly how China has been showing off working home grown Xnm lithography prototype chips that can compete with TSMC, but reaching the yields and volumes of TSMC is where the impossible to cross cliff lies, and why people get confused and don't understand that the major challenge lies in manufacturing at scale and not just the core tech that makes the widget unique.
I'm not defending e-ink the company and their corporate practices, just wanted to shed some light on the technicalities of the subject and hopefully clear some of the FUD and conspiracies that get wrongfully spread around.