I’ve been trying using my iPad for work over the last few months instead of my laptop – mainly for a lot of the reasons you mention above.
And while I generally love the hardware as an alternative to the laptop, I juts find what’s holding it back are the 3rd party apps. Mobile versions of tools like Outlook are missing a lot of the functionality that you’ll typically find on a laptop.
So, in my opinion, while Apple has done a great job building an alternative to the laptop, they’re now waiting on software providers to step up to the plate.