The link below is to an article that looks at reasons to upgrade from a Kindle App to a Kindle Ebook Reader. This is something that I did a short while ago (I did have a Kindle Ebook Reader from the start – which was no longer any good I should add), simply because I wanted something with a longer battery life. I would probably have been quite content with the app on my tablet otherwise.
For more visit:
https://blog.the-ebook-reader.com/2020/08/09/time-to-upgrade-from-a-kindle-app-to-a-kindle-ereader/