It's just convenience -- it gives you a single central point of control.
With the Hue app and a diyHue hub, you can control multiple "real" Hue hubs, plus a bunch of lights of various types that the regular Hue hubs don't support, and as far the app is concerned, it just looks like a whole bunch of compatible lights attached to a single hub.
And with hub mesh it becomes even easier, I imagine...
I suspect it is but I haven't tried the new hub mesh yet. Eventually I'll get a new C7 hub to move the bulk of my devices to. Then I'll redo everything with the mesh. I'll use one of the older hubs to use for potentially problematic integrations that might slow things downs otherwise.
Download the Hubitat app
