For the price it has, you could as well buy an iPad Pro, which will do literally anything the ReMarkable will do, but better.
Note that I'm not saying its better in general than an iPad Pro, because overall its not. The iPad does way more, but that's besides the point because this is a device with a very specific purpose.
The most obvious advantage is the paperlike screen that reduces eye strain. Not everyone wants an e-ink screen, but for those to whom it is important, the iPad's screen isn't an acceptable alternative.
The next advantage is battery life. It isn't as good as a kindle, but its better than an iPad Pro by a long shot.
The other advantage is weight.