Years ago I did wear a belt with jeans when I tucked in my blouses. Today, I seldom tuck in a blouse when wearing jeans.
However, I still tuck in blouses when wearing dress slacks and I wear a belt in the belt loops always.
Guess it depends upon the venue. If I'm casual and in jeans, no belt. It I'm making an effort to dress up, I always wear a belt in the loops of the slacks or skirt.
Money screams; wealth whispers.