Has been for a while, assuming you can get work done on the iPad UI. It doesn't do a normal mouse and there are some limitations to things like screen dimensions.
Works in a pinch but Apple is not going to compete with themselves on this front, they're expecting you to buy a macbook for serious work and an iPad for work in a pinch.
Buy M-based iPad, nice monitor, keyboard and mouse. Connect mouse and keyboard to monitor via USB. Then iPad via USB-C/Thunderbolt to monitor.
Everything "just works" and you can handle surprisingly high amount of work this way
If you are using an iPad as a second screen - you get the same app you have on your mac (obviously, iPad just acts as a second screen: https://support.apple.com/en-us/102597).
If you are using an external keyboard and a mouse with it - you will get the same touch UI, yes.
Many apps are missing many keyboard shortcuts that you may be used to if you’ve used the equivalent on the desktop. You’ll need to keep the iPad screen accessible to tap on UX elements. There’s also the issue that shortcuts that do exist may be hard to discover because there’s no menu bar to look in.
> Many apps are missing many keyboard shortcuts that you may be used to
This is true. To see the ones that are available, hold down the command ⌘ key to get a scrollable list of all of the shortcuts for the app you’re currently using, and use Fn-m or globe key-m to see a list of the system shortcuts.
Had no problems connecting iPad Air 4 to external display via USB-C DP. Have not check whether periphery devices work this way though - I used BLE keyboard.
