The iPad is in decline, and hardly anyone cares... except a handful of zealots on the MacRumors forums.
MacBook Airs are TOO GOOD
Luke Miani suggests that the iPad has tough competition from the MacBook Air product line. He's not wrong, but he also doesn't consider the iPhone Pro Max line. A lot of people are buying these jumbo-sized iPhones (including myself) as a replacement for an iPad.
Overly Complicated Multi-App Use
In trying to avoid the complexities of a windowed environment, Apple created something just as convoluted, or worse, than a windowed environment.
Single-window applications work and make sense on the iPhone. They always have. But that strategy doesn't scale up to a larger display, at least not without compromising most of its utility.
Too Small for Multi-App Use
Small screened devices are doomed to failure.
We learned that with the iPhone mini. People don't want small screens. Not now, not ever. Ever ever ever!
And so the iPad, with a screen smaller than most of Apple's laptops, makes it just plain unattractive for professional use. Why in the world would I want to edit video on a 12.9" screen when I can use my MacBook Pro hooked up to a 27" Studio Display?
Why would I edit text on a 12.9" display when I can edit text on a massive desktop display?
It's just unattractive. And no amount of marketing or zealotry is going to make downsizing my screen real estate enticing.
Even people who aren't technical feel/sense this. I observe this time and time again - when non-technical people have both an iPad and an iMac, they always reach for the iMac first.
Still A Non-Starter for Programmers
Aside from the small screen and overly-complicated multi-app use, I simply can't use iPads for most of my primary work, still today!
I wouldn't be able to publish this very article if all I had was an iPad at hand. I need python. I need node. I need something more than Swift Playgrounds.
Computers Need to be Flexible
In order for computers to be useful, they need to be flexible and malleable. They need to allow you to create and live in your messes. The Mac allows you to do that and is one of the biggest reasons why it has a staying power that the iPad never will.
I think probably the most gutting thing about the iPad becoming stagnant is that the iPad is as clear of a vision of an Apple product as you can get - a locked down appliance. It is everything the Mac was supposed to be, but the Mac could never be tamed and the Mac has been ever successful.
The Holdover
Remember when we were all pissed off with how Apple was neglecting the Mac in the mid-2010's? They kept calling the iPad the "future of computing?"
In retrospect, it's entirely possible that they were saying all of this because the Mac was so bogged down by Intel that they needed a product to act as a stopgap until the M1 Macs were available.
What Should Happen?
The iPad lineup needs to be thinned out to two or three configurations. The iPad should still exist for use as POS systems, or for pilots, or for people to buy for use in their kitchens. The rest honestly just need to buy Macs.