I got the 2022 Fire HD 8 to replace my 2013 Fire HDX 7. While the software on the new tablet is a huge upgrade, the hardware is rather lackluster (the decade-old HDX had an excellent display and processor, even by today’s standards). The Fire HD 8 is still perfectly usable for most basic tasks as long as you put up with occasional stutters, and the 8″ size is a sweet spot that is not too large for ebook reading but also not too small for watching videos. There are very few alternatives in the compact tablet market and pretty much none at this price point.
The display has a resolution of 1280×800, so it’s not full HD (compared to 1920×1200 on the old HDX 7 as well as the current Fire HD 10). The lack of sharpness is most noticeable with smaller text, but otherwise the resolution is not really an issue when reading ebooks (I use a medium font size) or when watching videos.