I think the bright cornet sounds might be fading away from the norm again. At least in the brass band setting.
Most are now back to a larger bore smaller bell and Wick 4. Which gives a very warm sound.
Even this year’s competition music seems to be focused more on sound and style than moving the fingers at 100 mph
As for bright sounding cornets....
I believe it’s because people think there trumpets and pop in a 3c and play just like the trumpet
Cornet is more style than anything
And it all depends on what kind of music being played
No cornet is bright with a Wick 4 plugged in
Bb & C Trumpets