Maybe it's how it's "supposed" to work in principle and by the books they're doing something wrong, but on the other hand, have why haven't other patented techn

Maybe it's how it's "supposed" to work in principle and by the books they're doing something wrong, but on the other hand, have why haven't other patented technologies ended up in such a limbo state? Lots of tech has been patented, some by ruthless and litigious companies like Apple, and yet somehow there don't seem to be that many broad technologies like electrophoretic displays that have ended up like eInk products. What makes these displays so different? (Edit: to be clear, I don't mean to sound snarky or rhetorical, I'm genuinely curious since these displays seem to be in a pretty unique situation)