There are some major challenges to getting there but I still feel the ultimate evolution of iPad and Mac is a device that flips between two modes of work depending on whether it's docked into its keyboard. You can squint at the iPad today and see Apple trying to get there, with trackpad and keyboard input available on iPadOS as long as you have the right accessory, but there's a long way to go yet. And I'm not even sure the juice is worth the squeeze, to be honest. Maybe they should be separate devices.
I like: "And I'm not even sure the juice is worth the squeeze, to be honest." Never heard that one. But, it is a good way to put it. Yes, maybe they should be separate devices.
You can buy a base M2 MBA (256GB) for $899 on sale. You can get a base iPad 10 for $349 on sale. That's $1,250. You will probably spend close to that or more for a 12.9 iPad Pro with 256GB storage plus Magic Keyboard on sale.
With the MBA + iPad, you have two portable screens. More real estate. You have a device and OS designed for content creation and multi-tasking, and you have a device and OS designed for content consumption and app centric single tasking. Both are optimized for their respective tasks. BTW - content consumption is a very important part of the productive workflow for many professions....nothing wrong with having a device that excels at it.
Anyway, more power to those that find they can work effectively with an iPad only. I don't doubt it. There are many ways to get stuff done.