I've actually seen that video before, and the main limitation is still the pixel transition time. It's something like 200ms, so any sort of motion will have heavy ghosting. It's definitely a huge improvement over most controllers though.

If all you do is read/look at static content, e-ink is great, and that's why it's used on all the e-readers. I wouldn't want to be taking a video call on one though.

Tandem oled screens are also starting to become more of a thing, and that improves the usability in direct sun. But I don't have any problem using my phone outside as it is. I'd rather just have a bigger battery than a worse looking screen for what I do.