> Illustrating sucks on those platforms [...] They aren't good for scanning QR codes [...] They are bad at being held with 1 hand or being used with cellular connectivity

All of these are form-factor complaints. macOS, Linux and Windows all support every single feature you just listed, it's just that people don't buy hardware providing it. Conversely, the iPad has these hardware features, but is widely criticized for only supporting an OS that is markedly less-capable than macOS. iPadOS is a derelict wasteland lacking USB class-compliant hardware drivers, basic graphics APIs and any of the escape hatches that macOS offers to power users.

I just can't see how anyone can make this argument in good-faith. It is consensus that iPads are less capable than Macs, and most people will blame the iPad software more than the hardware. iPads are artificially restrained by a weak, incapable OS that prevents the hardware from cannibalizing Mac sales. iPads might win on a convenience factor, but they will always lose when comparing capabilities. It could be argued that iPadOS has a grand total of zero redeeming features.