Every point of conversion rate and every shekel of AOV raises what a single click is worth to you. What a click is worth decides what you can afford to bid. What you can afford to bid decides which auctions you win. That chain is the entire physics of paid media, and only the first two links are under your control.
So the funnel work, CRO, AOV, offer crafting, the flow behind each offer, is not polish that happens after growth. It is the thing that makes growth affordable. A tuned funnel lets the same campaign bid higher, win more, and still hold margin. An untuned funnel makes every scaling attempt a race between volume and losses.
That is why the loop runs in this order. Amplify pours into whatever the funnel is; Tune decides what that pour is worth.