Using a lens like the 24-200 sort of makes me start to wonder what the point is of a system camera. Although that feeling would be stronger with a 28-300. Also I do think the 24-120 isn’t necessarily less versatile than the 24-200. The versatility is just different.
I get your point if someone only has a 24-200 and never removes it from the camera. And that certainly is something super-zooms are fairly criticized for at times (especially the classic expensive DSLR body with ultra-cheap low-IQ superzoom welded to it).
But of course if one pairs the 24-200 with some primes or an UWA the advantages of a system camera are quite clear. A similar criticism could be made of folks who say "I sold all my primes after I got my F/2.8 zooms". Do you really have a system camera just to swap two zoom lenses on and off?
Actually the number of people I see who have the 24-200 along with some other 24-xxx zoom and use both highlights how something like 24-200 extends the usefulness of a system camera even if it overlaps in focal range with existing lenses. The 24-200 allows you to turn your system camera into an extremely high quality all-in-one for things like hikes or daytime travel outings where compactness of your kit is essential. Come nighttime you can swap over to faster glass, be it prime or zoom, for astrophotography, indoor lowlight photography or nighttime street photography where aperture trumps focal range for utility.
And actually even for those size/weight restricted day outings something like the 24-200 plus the 40/2 makes for an exceptionally capable kit.
I've been a multi-camera/system shooter for years and years but really in any case that I can have a lens allow me to remove another body/camera from my setup all the better. The 24-200 does that for sure by letting me use my Z7 in cases I might have leaned on m43 instead. And I expect the 24-120/4 will do that as well for a different set of users.