GoKawiilE Ink tablets make the most sense when reading and drawing are your primary goals. The technology is believed to be easier on the eyes compared to the displays you'd find on mainstream tablets like the iPad. E Ink is a reflective display rather than an emissive one, meaning your eyes don't have to adjust to bright light being emitted directly from the display.
In fact, E Ink shines outdoors since it relies on reflecting external light sources to make the contents of the screen visible. Lower-end iPad models, meanwhile, tend to struggle under direct sunlight as their backlit displays lack the brightness necessary to overcome the harsh glare of the outdoors. The iPad Pro fares much better in this regard, though, thanks to the high brightness levels of its tandem OLED display.
Many E Ink tablets also feature matte displays rather than the glossy glass surfaces you'd find on the iPad and other conventional tablets. This adds to the paper-like appearance and feel under your finger or stylus.
Finally, you'll find that some E Ink tablets like the reMarkable Paper Pro deliver better battery life than an iPad, at least in active use. This is because these displays only consume power when refreshing or displaying new content. So if you're reading content, an iPad has to continuously power its display while an E Ink tablet can enter a low power state between page turns or scrolling. The simpler construction and lower power requirements of these displays also allow manufacturers to build lighter devices.
All told, E Ink tablets can be more comfortable to use from a visual, and even ergonomics, standpoint. But that doesn't mean it's without its flaws.