They’ve messed up Books on the iPad as well - by what looks like removing or crippling Pro Motion (120hz). Now, when scrolling, you get a noticeable ghosting effect on the text. It’s horrible. They also seemed to have changed the display driver/colour - it just seems a tiny bit greyer, and I hate how they’ve now removed the automatic highlighting when using a pencil 
You now have to highlight text > Click on Highlight > choose a colour!!! 
Previously you just needed to highlight text and it would highlight (and you could change colour afterwards). I loved the Books app (and my iPad) before this. I regret upgrading to iOS16 and use the iPad less because I hate the ghosting (present even in Safari).
This is one of the biggest things I hate about Apple - they purposely or complicity introduce obsolescence with each OS update. It’s the same on macOS and iOS. It’s hard to imagine this sort of thing happening if Steve Jobs was still around!