You've looked at the pure mechnics of it but not the actual utility of it. Yes I can dump years worth of datainto a moleskin. Now I want to challenge you to find anything specifc in that pile of paper. I could do it in a few seconds, share it with people, import their pages, pull in my books, extract information from them and share that, etc.

So if you have a small amount of paper - forever, maybe what you say is ideal. But if you are like most people,you have notes on random pieces of paper in random notebooks and stickies all over the place and going bac and extracting information from your information is a massive chore.

That's why these devices exist an why tey can charge a premium. Ive not yet been willing to pay that premium, but I absolutely see the value - same as I see it for Notion/Obsidian and the like.