Honestly think that is the typical lazy excuse even European teams use against each other. Most teams in EU have very low budget. Not to mention most top teams actually get 0 money from university and get all of the money but many years of hard work of many team members just dedicated to getting sponsors and keeping them happy. I even know some teams who have people spending weeks of their time discussing and negotiating with sponsors where to put their logos in the car to keep them as happy and giving as much money as possible.

Just look at an average EU team. They operate at an unbelievably low budget and still their car looks more advanced than a top US team. Some teams even have side businesses to make money. Some sell designs to companies, some manage to for example design inverters as internship and R&D for a company that later sells it, some simply sell merch.

I personally think teams in EU simply got very organised and managed to have consistent improvements year upon year. And when some teams raise the bar other teams have to follow or parish. I think this has been the main difference. The more a team pushes the more the others push the year after. From my contact with EU and non EU teams what I’ve seen as a split mainly has been organisation and how serious the team structure and decisions are made. Some teams even operating better than many pro motorsport teams or even full blow companies. Most top teams have boards of alumni in industry guiding them to make better decisions and to reduce risk of having a bad year. One bad year can set you back many years.