If I don’t lose the ball I usually can get 2-3 rounds out of a golf ball until it is too beat up. If I am playing in a tournament I’ll make sure the golf ball is new or in excellent shape. For a normal, weekend or weekday round, I am a little more lax in how pristine the golf ball needs to be.
I do love the feel of hitting a great drive with a fresh golf ball knowing I’ll get great performance.
I carry the same golf ball in my bag, I don’t switch type of golf ball from hole to hole or switch due to water or hazards.