I can't imagine trying to do that on an iPhone. Surely it's useless.
What this does do is reveal the fiction that "iPadOS" and "iOS" are separate. Clearly not.
Just as a N=1, I would rather pay a recurring fee in the Disney-Netflix range to Apple to get more liberty in usage from my machines. But I think they don’t dare to go those routes, because they need the broad market base and cannot extract the current cash flow from a smaller base, while setting expectations that the Googles, Samsungs can copy.
Industry leaders dilemma. Apple currently settles on market differentiation via physical products.
Not saying you are wrong, this may be the reason Apple operates nowadays, but I maintain it is shortsighted.
Two bits floating in my mind: I'm in management (different sector, totally different scale) and deciding to move forward against a market as a market leader is a really scary decision. We did and changed our proposition against a trend in the market. The market mostly followed our lead. Thats what we hoped for, but sure couldn't count on at the time of the decision. So we had to make sure to have all stakeholders involved in the risk - What if most of our customers just left? Then suppose you are in management for Apple. The stakes are massive. How would you communicate this shift?
The other one is: You should take the strength of your opposition into account when making bold moves. Android / Google / the brands fabricating the products I would say (no need for the old debate) are market followers. They are good at following and produce more technical diverse products, minus the margins. If you do not expect your opposition to make the bold move first, but do expect them to follow your bold move, I would argue you should be less likely to play bold moves unless you know they cannot follow you. So game theory I think also favors the status quo for Apple.
Replacing the MacBook + iPad with an iPhone + some dock accessories might reduce revenue per customer.