I use a Kindle Scribe almost every day, have read dozens and dozens of books and documents on it. Maybe we have different expectations but I love mine and take it everywhere. It's never crashed.
When I am trying to focus on reading a book, I appreciate that the Kindle doesn't have too many bells and whistles. I don't want notifications popping off and the distraction of fast Internet access.
The Kindle Scribe is way more expensive than normal kindles (and has to handle the more computationally demanding task of vector graphics), so it would have a faster processor, and would be able to handle ebooks way easier than a cheap Kindle.
Not saying you're wrong, just that your anecdote doesn't mean much about $100/$50 Kindles.
When I am trying to focus on reading a book, I appreciate that the Kindle doesn't have too many bells and whistles. I don't want notifications popping off and the distraction of fast Internet access.