Apple

Well, with macOS there are layers to what the user can do. You can stick to apps (most), or you can open up the terminal and the console and use the machine at a significantly lower level (ie, "hacker" unix/bsd style).

I haven't used an ipad in ages ... but AFAICT It seems slightly dumb that they don't just open up a similar possibility with the ipad for those who are happy to go there. A mode that is literally just "Laptop" mode ... full macOS with mouse cursor and the full functionality. Then when you want to just browse and read etc, hit a button and you're back to touch based iPadOS. At this point it should really just be a different UI skin.

The reality though, I think, is that it's about market segregation (ie monopolistic money).

Apple, like Microsoft, Amazon, Google etc are all "IBM-ified". More about squeezing their well established market positions than doing anything remotely risky or interesting. A fusion ipad/laptop is the sort of thing a younger company would have done by now (with of course microsft having tried that ages ago).