Flipping pages
If we had e-ink readers that allowed to quickly scan through piles of documents, good search capabilities and cheap enough to have a pile of the on the desk, then paper would be gone in an instant.
I have cut down on my paper notes massively with reMarkable 2. Unfortunately this thing is so slow, it does not let you meaningfully go through documents. There is also no way to quickly search through your notes - again, it's too slow. But you can always have some sort of a naming system or just search on a computer.
The deal breaker, however, is lack of encryption. That is you can't really use it for anything sensitive and definitely not for business.
If someone solves this problem, they could become billionaires, but make no mistake - paper lobby is still strong. They had enough influence to outlaw cannabis cultivation worldwide, they'll have no problem whacking someone trying to kill their paper tiger.