Agree with those comments about the cart being more work on hilly courses.
But, other advantages of carts are keeping the everything off the ground when it's wet, and (depending on cart design) giving easy access to your discs without bending over so far. And also (again, depending on the cart) a seat!
I saw an interesting solution by Big Jerm on a practice round video earlier this year. He carried a lightweight camp stool and put his bag on it instead of on the ground. I immediately tried it with my tripod stool, and it didn't work. The seat is too small for the base of the bag, and the three legs don't give study enough a base. Ski either the bag would fall off, or the entire thing would topple over (once during my reachback).
That got me searching for inexpensive four-legged camp stools like I saw Jerm use. Almost everything I could find was too low: 18" - 20" high, so I was still bending way over.
I ended up buying a camp stool for about $20, and bought some PVC pipe to extend the legs, and some black spray paint to make the extensions blend in.
Works great! I carry the backpack as I normally would, and the stool folded, over one shoulder. Lots of the convenience of a cart without the weight. And no harder than just a backpack to carry on hilly courses. And I still get a seat!