I have both a Kindle Colorsoft (1st gen) and whatever the latest gen Paperwhite is and there's a noticeable contrast difference, but not nearly as bad as shown in that image. I find lack of sharpness to be more of a problem for very small fonts than the contrast.

I actively use both. I toyed with getting a Scribe because I read a lot of full size PDFs which aren't a great experience with such low refresh rates and small screens, but opted for an iPad instead. I owned a ReMarkable 2 a few years ago and don't really have anything good to say about it.