Cell phones are better. They've figured out obvious things like screen rotation, adaptive brightness, bluetooth audio handoffs, and Android has made some headway with things like darkmode and automatically changing settings when you get into a car, but tablets have lagged behind, and I'm sure there are dozens more tiny things that automatically changed based on the device's context.
This always works fine for me on my SP6.
That would be excellent. iPad needs a local web server capability for development, e.g. to run Jekyll/Ruby or Hugo/golang. Rumor is that upcoming Apple Arm CPU will support hardware virtualization, which could theoretically enable Linux to run in a sandboxed VM.
As for UX, the new iPad Magic Keyboard is a game changer that seamlessly blends tablet and laptop. Now we need to address the iOS gaps (e.g. Xcode, non-Safari browser and mail client) and/or allow dual-boot as you suggested.