pasta sauces made with canned tomato base taste so much better than pasta sauce from scratch
That's a matter of taste, to say the least. You could probably come up with all sorts of metrics that show that canned tomatoes have more of this or that, but pasta sauce made with fresh tomatoes taste like tomatoes, canned tomatoes taste like imitation tomatoes or almost like ketchup in comparison. It sounds like you might've not reduced the fresh tomato sauce enough or something.
I won't deny that I use canned 99.99% of the time though. They win on every metric except taste.