I use an iPad Pro as my daily work device. It spends most of its day hooked up to an external display with an M&K as the main interface. I use it because my work PC cannot run the software I need and I’m waiting for IT to get me a new one.
In all honesty I prefer it. It’s faster for most tasks. I can push it with CAD and Video processing. It’s great to be able to photograph a material or experiment and then annotate it for emailing straight on the display. Face ID is so much quicker than the tiresome Ctrl+Alt+Del. I can take it home or on the train and have the exact same workspace waiting for me.
Admittedly I can do most of that with a laptop but the addition of a LiDAR Scanner, direct 4K video recording, photography and audio recording mean I don’t also need thousands of pounds of extra equipment to use it for anything.
I think the reason the Surface hasn’t been doing so well is it doesn’t have a defined use case. The iPad sits at the $400, $600 and $800 price points in Apple’s computing lineup at a ‘good, better, best’ range. Yes the iPad Pro is also marketed as an accessory to desktop owners and artists but the regular and Air models are more for people who are willing to sacrifice a little control for a more managed experience. I would strongly argue that at $400 the iPad is the best computer you can buy.