We have a bunch of Christmas markets in the US. They get pretty packed. There are parking garages near them since their downtown in major cities (DC, Baltimore, Philly).
Garages are better than lots. Especially garages under buildings. No Americans have been tricked into anything. None of us have a say in how our cities were designed. That was mostly auto makers at the turn of the century.
We have a pretty sweet stadium in downtown Portland. It only holds like 22k give or take, but there's no parking lots and light rail service is basically across the street, so we get a real old-world vibe there. Plus the Timbers Army is probably the biggest and most well-organized supporters group in anglophone North America. A Timbers match is definitely worth the price of admission if you ever get a chance to visit. Preferably on a rainy weeknight if you want the real Pacific Northwest experience.
For one they are much larger in size, which is the whole argument here. They do civil engineering and public transport better.
They have much more tradition. Having been to many on both continents, the ones in the Americas are much more of a money grab than a celebration.
In Europe it's a bunch of people standing by stalls eating their favorite seasonal/traditional food listening to music and chilling around with family, not buying local goods/stuff. That's for tourists.
In the Americas it's long lines of people, moving them through and out of the market after they purchased outrageously priced common food items slapped with some sort of german/chistmas/winter spin to it. Minimal decoration and theme to call it a Christmas market.
For one, Christmas markets in countries that traditionally do them are significantly larger. The largest ones in the US would be a mid size one in Berlin.