The Noble/Dark Confidant/Thalia/Mayor core creature base for Humans designed 5-6 years ago (A_Duck and myself worked months on this) has been utterly destroyed by printings like Walking Ballista/Wrenn/Oko and more. You get punished so hard by running the 'normal' stuff.
Some answers I can think of are:
They print an efficient card that hexproofs our investments (our creature base) is to play more powered lists yourself that generate more resource than they can handle. A good example is
The problem is that this card is not efficient , at 4 converted mana cost it is a good card, but in order to be reliable as a tactic to support our strategy of 'protect the investment' it has to be cheaper. Cheaper with a price maybe but it has to be able to get in there when it matters. Similarly how infect tries to protect their dudes.
Chubbyrain has illustrated that a list with Humans and lords can get the job done: https://www.mtggoldfish.com/deck/3167642#online
I do not know what the match ups where, and I am especially interested in the match up vs Wrenn/Drs. It seems that his list tries to put a lot of boots on the table and win by force and relatively quickly. Having access to Humans that can grow big but do not cost 3 mana (like Knight) was most likely what made life hard on all the decks that try to get rid of all your stuff. Very interesting list.