I cannot help but think of the Ship of Theseus. If Apple were to change so much of the iPad we'd just have a MacBook which is not what the product is supposed to be. If Apple thought a MacBook with a touchscreen would sell they would have built one by now, surely?
A million different things to a million different people, the iPad is more of a swiss army computer than the Mac will ever need to be. I use the iPad Pro as my main work computer and can only do so because it's not a laptop https://carlst-james.medium.com/how-i-use-the-ipad-pro-to-do-actual-work-aac65c7d6e39
I won't say it's perfect though and yes iPad OS 18 should bring some changes. But these should be more about eliminating repetition interactions and making better use of screen space. Why do Stage Manager and the Dashboard have the same gesture? Why have stages at all when the multitasking screen does the job? Why is Dashboard only one column? Why do notifications still take up the whole screen?
(The reason we want the Watch App on Mac and iPad is so we can transition from the iPhone. Using a Watch for base communication and an iPad Mini for anything with more depth is the dream!)