That says nothing except the sad state of the other native apps you use in your workflow.
The truth is that yes, indeed, I can find a lot of native apps that are just about as "good" as slacks native Mac (and iOS - it's really bad too) app, and I can also find a lot that are a lot worse. But why compare to them at all? We should be measuring how good an app is by comparing it to, in this case, the best of the best native apps on the particular platform, or across all platforms, if so desired.