Apple knows how to run a business and for that reason, the iPad Pro will never be a laptop replacement.
The iPad Pro will always be between the iPhone and the Mac, because of $$$$.
It makes no sense for Apple kill off their Mac lineup.
iPad OS 15 has confirmed this.
You’re right, it doesn’t make sense for Apple to kill off the Mac. (Also there hasn’t really been any indication that they were ever thinking about it.) Sure, it could be because of money. But it also could be because functionally Apple doesn’t see the Mac as replaceable. It’s already the best desktop/laptop they believe they can make. Therefore trying to replace it with anything else will, in their view, be worse—otherwise they would have already replaced it with that thing.
Apple makes Macs and iPads each with their unique focuses and unique sets of strengths and weaknesses. There is no one unicorn device that can have it all, otherwise Apple or other companies would have made it already. The Surface is an attempt, but it comes with its own compromises. It works for many people, but seeing as more people seem to stick to regular laptops than Surfaces, it seems most don’t agree with the Surface’s compromises. So Apple’s view also seems to be that for the vast majority, laptops and mobile OS tablets work better as separate devices.
I think some people are just frustrated that their iPads come very close to replacing their laptops. But the thing is, for many people the iPad already replaces their laptops (or can)—and no matter how much functionality Apple adds to the iPad, there will always be a fringe group that needs “just a little more” in order to replace their laptops. Unless Apple makes the iPad 1:1 as functional as the Mac, there will always be that fringe group. But if Apple made it 1:1, then the iPad would lose its identity as a simple, easy-to-use device. Robust functionality and ease-of-use are on opposite ends of a spectrum, which is why Macs and iPads each have their strengths and weaknesses.