The .280 was a flop when it hit the market... That tells me all I need to know..
All it should tell you is that the timing and marketing was mishandled. Sales numbers do not always tell the whole story.
To be mentioned/compared in the same sentence as the 270Win, 30-06, & 7mag puts it in very good company. Those three aforementioned chamberings were three of the reasons for slow 280 sales.
It might have been a sales flop, but the 280 still ranks near the top for North American BG cartridges.