Album Art is still around. I keep that separately from the audio. I use it also as a record of the order of tracks on an LP.

2. Digital books can’t be skimmed.

Very true. That's probably what I miss most too.

But I see that as an offset. Many books I've had that just sat there year after year on the shelf, getting yellower and dustier by the day.

Did I mention that I'm an 'information hoarder'? I still have files on my archive disk from 40 years ago.