Economy is insanely important. How much gold should your players have at level 13? What magic items are they expected to have? What determines the availability of any random thing? If there is an imbalance between what is expected and what they have the game is either way too hard or way too easy. Economy is vital and is more than just money.

5e does not have balancing. The chart they give you in the book is so stupidly off i have to wonder if the designers ever played their own game. If you go by that the players will never be engaged, it’ll just be wasted time.

Those were two separate complaints, btw, no matter how well they feed into each other.