An iPad (or tablet form factor) is excellent for consuming content on the internet, which includes eBooks amongst movies, reels, articles, blogs, news etc.
I've got a paper white and while the browser on it is decent, and you can email yourself PDF's to view on there - it's still a subpar experience for anything that isn't formatted to display as an eBook on an e-ink display.
Don't get me wrong, I love reading on my kindle and it's far easier on the eyes, but it doesn't do what an iPad does in the same way reading a book on the iPad is more tiresome than on a kindle.
Have you tried reading content on the web on the kindle, as the ones I mention above?
That said: a tablet wins out where I need to sit down with the docs of some technical monstrosity for a dedicated hour.