I don’t see how macaroni implies being cheaply made and spaghetti doesn’t. Both are just pasta.
Macaroni generally has an association with cheap Mac & Cheese box meals. I do agree that, on a broader scale, they are both pasta and not really functionally much different.
A very American association. Here in Germany for example, macaroni are among the more premium pasta variants (not expensive but not the cheapest around). The cheap (and most common) noodles are actually usually spaghetti, fusilli and penne. Mac n cheese box meals are not really a thing here.