Maybe leveraging those Content Delivery Networks will let you get away with it. But maybe they won’t.
Consider, too, the weight of code that isn’t being written directly, instead being added by plugins and addons. Analytics, advertising, and retargeting scripts tend to consume far too many resources each — combined, they’re a recipe for a website that’s disrespectful to its users by being bloated and invasive. That can’t be saved by code minification.