Of course, humans could, at any time, introduce things to make their lives more efficient. But when we consider post-scarcity humanity, we must also note that time is no longer scarce. Efficiency is meant to save time. But their time is infinite. Why try to save something you have in infinite supply? You may as well tell them to dig up dirt and hoard it in boxes.
You haven't been awake for long. I think you underestimate how exhausting it is to think big. You can only hold grand ambitions above your shoulders for so long before you get tired.
They got tired. Some lasted longer than others, but they all got tired.
Now they are resting in a moment that will last until the end of time.
