i'll never give amazon a single dollar for ebooks but i source tech for a lot of people who arent used to there being alternatives yet or think its still pretty difficult
as others have mentioned the battery health thing is what makes phones difficult. im comfortable working on phones though so i usually offer them to people like "i have a pixel 3a sitting around that you can have for the cost of a battery". ive also got a 2nd gen kindle laying around that needs a new battery. considering hacking in a smaller cell if i have one. old ereaders usually cant connect to their servers anymore but that doesnt stop you from putting drm free epubs on them over usb