With some sort of pulley, rope allows a single human to excert large amounts of force trough leverage, often in ways more convenient than other forms of mechanical leverage. (Such as actual levers.)
Rope can also be used for 1:1 power transfer.
The wheel is overrated. It isn't that innovative (having been invented many times throughout history by various cultures) and to be properly useful it needs environmental adaptations. Controlled fire is neither under- nor overrated, I think.
One has to wonder how many times they had to be a conceptual leap too. Rope could've been "invented" hundreds of times over the last 100,000 years, depending on how lossy knowledge was.
Surely, if ancient humans could understand and then predict the seasonal movement of the stars to plan agriculture, they'd be able to work out that there is a linkage between sex and pregnancy.
Pottery.
Can't have soup without pottery. (nit: you can use some sort of leaf bowl but like, eh)
Indeed, we've largely missed the point of the "David and Goliath" story. David rolled up to a sword fight with a handgun.