When the iPad came out, it felt like a burgeoning third revolution, but a decade-on much of that potential has been squandered. None of this is to say that the iPad hasn’t been a success, but that it hasn’t been all that it could be. The real opportunity is for the iPad to be the best of both worlds: taking the modern aspects of iOS and combining what worked well on the Mac, and turning it into a device that’s more than the sum of its parts.
There are people who will say "the iPad was never going to be anything more than it is today," to which I would say bugger off.
The iPad has undoubtedly filled niches that were not well-suited by traditional PCs (Macs included), and its sales numbers support that: despite having a much lower average price, both the Mac and iPad each accounted for 9% of Apple's total revenue last quarter.
I think what's disappointing about the iPad is that while Apple debuted it as the "middle device" between your Mac and your iPhone, it quickly became clear that this could be a full-on replacement for the Mac for many people. iOS was such a better experience for most people, of course a laptop-size version of it could be The Computer for Everyone, even if nerds kept getting PCs (again, including Macs) because they needed/wanted more power and control.
Apple got us going with the debut of the iPad Pro in 2015, which pushed its pro bonafides, with Apple running ad campaigns with lines like, "your next computer isn't a computer" and the now-infamous, "what's a computer?" This was followed by the Magic Keyboard, mouse control, and now Stage Manager. Their preview page for iPadOS 16 even brags about "desktop-class apps" coming to the iPad this year.
And yet the iPad always feels just a bit short of achieving this goal. Again, I know it sells a ton of units, and I own one myself, but it's hard to look at the iPad and not see all the potential it had feel unachieved. Apple loves to tell us about pilots using the iPad mini and artists using the iPad Pro with the Apple Pencil. It's a good auxiliary device, no doubt, and I too enjoy the iPad for some tasks in my life, but the iPad seems doomed to stick in the lowest-common-denominator category forever. If you need something simple, then the iPad has you covered. Want something more complicated? Ooh, the iPad may not be what you want…
I think it's a bummer that software innovation seems to be happening on the web far more than it's happening on the iPad these days. Many new services don't even have an iPad app, or if they do, the general advice is that you'll get a better experience on a desktop PC.