I would love, for my personal use, to replace my MBP with an iPad but it just won’t be possible until there is some method for executing arbitrary code, which I see as a requirement for software engineering. Even if they just made Virtualization.framework available so you could spin up a Linux VM so things were totally sandboxed, I would be able to actually use the thing as a computer.
The reason for preferring this over a MBP comes down to several reasons: touch, form factor, pencil support and honest for “everyday” use, iPadOS is better than macOS.