If there was ever a time to do this it would be right now as they undergo changing Mac to ARM, but they're not.
The real question is if they can convince all the professionals those companies cater to to adopt an ecosystem where software providers have to go through an arbitrarily and closely controlled App Store.
If their hardware and base OS is too attractive to those professionals relative to the loss of freedom Adobe, etc. will follow.
Thankfully, though, I don’t think Mac users will actually be ok with that. There’s been quite an exodus of professionals from Mac to windows based on much smaller things so far.
Why not ? It's probably only a matter of time.
1) Apple has much more leverage on iOS because it has a bigger market share and many more iOS users than macOS.
2) macOS has traditionally been an open platform
3) Many desktop app developers wouldn't be able to keep installing and running the products the way their do it now. For example, Adobe has an app called Creative Cloud that manages installs, licenses, active computers, and other things. It's practically malware at this point, but if you want to use Adobe apps there is no other way.