There could be a second life breathed into Macs if they decide to switch from X86 to ARM architecture. Since Apple now designs best ARM-based CPUs itself, switching to the in-house CPU would allow for a hybrid device similar to Microsoft Surface. When this happens, MacOS in its new incarnation will become much more prevalent than it is now.
Having been extremely excited about iPad back in 2011, I tried to replace my Macs with iPads but gradually realized that the iPad is no replacement for the Mac. Even with the latest iPads Pro, they are extremely limited by iOS limitations. I see no reason to upgrade my iPad Air, and in fact, the iPad is no longer being used in my household. If Apple were to release a hybrid device similar to Microsoft Surface, I would rush to buy it on the release day, and I’m sure there will be millions of people doing the same as long as the device can be used with external monitors and a pointing device and run current macOS applications (even if in an emulation mode).
I would pay $1500 for such a device without much hesitation. I do a have a lot of hesitation paying current prices for Apple laptops that have only one port type and prefer older design, such as mid-2015 MacBook Pros. The concept of just a few USB-C only ports would only make sense to me in a hybrid-tablet form factor.