I wish TCL would stop referring to it as electronic paper, it's a matte LCD with some desaturated modes for eye comfort.
for me, the major selling point of a true e-paper display is sunlight readability, if your "electronic paper" LCD cant match e-ink, then it's not good enough.
The main E-ink patents are due to expire in 2026, so we should see some rapid development after that.
I love my Boox Note 3. It's am older device but still gets updates lots of tweaks for tuning the display on a per app basis, runs Google apps etc. I use it mainly as a reader for books and manga but also for drawing notes and browsing the Web.