You cannot compare multiple smaller nations to one nation. It is much easier for small nations to implement technology, rather than implement it across the vast US.
I don't think you are grasping the vast land size of the US. Notice I didn't just quote the population or just the land size, it is a factor of both. The 3 largest States in the US alone account for most of the main area of Europe:
I lived in TX, if you really want to understand the size of the US, you should drive from eastern most TX to western most TX. I've done the drive from Port Arthur to El Paso which is 834 miles (1,342), this will give you an idea of how big the US is. In this drive you will probably spend 200 miles in cities, the rest is all empty/farmland. TX is MUCH smaller than our largest state Alaska (which is 2x the size of Texas).
My parents live in Florida on 25 acres of land. They only have DSL (1 MB download speeds). Their neighbors (5 of them) have properties much bigger than theirs. Not sure how many middle class people in Europe have land that size, but it would be WAY less than in the US. All of this, makes it difficult to implement technology. A good example is, in order to use their land to route anything (utilities, internet,...) it is a very long process where they have to pay my parents a LARGE sum of money. Where does this money come from?
Here is a map of the continental US overlaid over Europe (not even accounting for our largest state Alaska, Hawaii, and our other territories)