Large is a relative term.
It is like saying your a “big” bettor - to the guy working for $14 an hour - a $500 bettor is big bets…to many it’s rec play.
Carry a balance - but I’m at below 20 percent utilization and my balances are on my interest free cards and credit union cards - the Delta Premier gets paid in full monthly as does the hotel rewards card. It’s nice never paying for flights/vacations because of the free points. When I traveled for work - the balances I ran up were great. Still got a few hundred thousand points banked.