The Kindle isn't a bad device on its own. Personally I use a Kobo. But I never pay for any ebook that I can't keep indefinitely one way or another.
I also have an old Kindle 4 that needs to be jailbroken before the May 30th deadline. Maybe I'll do that today. Gets you out of the ecosystem. And old Kindles can be found pretty cheap.
When Amazon started locking it all down last year I bailed on their ecosystem for Kobo’s store, but I use a Boox device. As long as I can back it up in any format I’m happy, and as soon as Amazon crossed that line they lost my business.
the drm is the reason why I never bought any kindle along with the relatively small non-expandable onboard storage, though the dx was tempting to me for a bit. I've stuck with Kobo, Pocketbook, and reMarkable and have been happy with them.