As we can observe in most images about the Venice Carnival, the Tricorn was used in those times by almost every man who could afford to buy it. Even the young kids helping the magician here in this engraving would wear one.
It was the typical men's hat used all over Europe during the XVIII century, then it fell out of fashion.
One of the non-secondary advantages of the Tricorno during Carnival, was that it would hold the Bauta mask in place, so no need of straps, more comfort for the user.
The Moorish Street Performer caption:
"O'la gente che qui stassi raccolta
Del Moro ai canti,
et i detti strani intenta:
Movendo a riso chiunque
il mira e ascolta
Della Piazza il trastullo egli diventa."
"See the people gathered here
From the Black guy's songs,
and which is intentely listening to them:
Making everybody laugh all
who look and listen to him
Of the Square he becomes the fun."