Quite the opposite, it is a complex mess.
Why is this bad? Well for one example, because sometimes you use version numbers not exactly. Consider the statement: "Applies to 11.0 and higher". Depending on how the OS identifies itself this will be valid or not. On the same OS.
Or consider reporting, if under some conditions the Mac identifies itself as 10.16 and in others as 11, you're going to have them in 2 different buckets even though they're the same thing.
Really, they should have made a choice, one or the other. If software wasn't compatible because of this it should just be updated. Apple never said it would always be 10.x.
I don't really understand why they're doing this as Apple normally has no issue telling developers to fix it or stuff it. They never cared about backwards compatibility before. If having 11.x was not that important to them to upset a lot of stuff, they should have just stuck with 10.16.
This is not true. While they may not have the slavish devotion to backwards compatibility that Microsoft has, even Apple implements app-specific hacks to keep non-compliant software compatible with newer versions of macOS https://worthdoingbadly.com/appkitcompat/
In fact most Enterprise software for Mac (think Palo Alto GlobalProtect, Zscaler, antivirus packages) are horribly badly packaged and I expect many issues here.
PS: Good point from tobr below too.. These things are not as simple as they seem.
The trick of checking version >= 10.16 to cover both 10.16 and 11.0 would not work then, as version >= 10.17 would cover 11.0 (10.16) too.
Then what..?
I use both AirWatch (now VMWare Workspace ONE) and MS Intune (now Microsoft Endpoint Manager) right now.
The problem is that they incorporate different technologies. For example, Workspace ONE includes Munki for its app distribution but MS does a different thing. Also many run scripts in the background to check things, which may or may not do things differently.
I haven't really tested Big Sur much with the MDMs because there isn't much point until all our antivirus software etc is updated to support it. But I'm pretty sure this will cause additional issues, and Macs in enterprise are already very difficult. Mainly because of Apple's consumer focus, enterprise manageability is always second place unfortunately.
Source: Microsoft Employee
The reason is that Apple actually applies marketing to their iOS version numbers, but doesn't do the same for macOS, because incrementing the minor version isn't marketable. Their crack marketing team does come up with funny names for macOS releases, but few people remember the mapping between those and the actual version numbers.
And it surely doesn't make it worse than the alternatives...