It's a processor and a screen. There's nothing about the physical device that prevents it from doing well at reading ebooks or comics. It's purely software. Forcing me to carry both a tablet for reading and a tablet for writing is ridiculous, especially at an ~$800 price point.

I can't mark up documents in a paper notebook, but it's marketed as one of the chief uses for Remarkable. Why? Because it's not "a paper notebook" it's electronic paper -- ie it's meant to do everything paper does. If I can print it out, I should be able to read it without much trouble, and would expect a good experience doing so for such an expensive device.

You don't have to go full Boox with the entire Android ecosystem to do that if you don't want to. But as an example of what a great reading experience on epaper can be, I'd refer you to Neoreader from Boox, the default reading app on their platform, which has excellent support for epub, comic books/manga, and PDFs.