Because grocery prices across EU/Europe vary by a huge margin, and going out for a drink /coffee even more. Nowadays things are getting similar due to poor countries getting better, and old powers stagnating in comparison. Logistics and what is produced nearby used a big factor (also local brands, different countries used to mean different brands), again due to trade agreements (trade between EU countries) and infrastructure improvements. So you won't find a lot a price and availability difference in what you used to find pre-euro, but there's still some difference, just not as choking.

Also, USA salaries tend on the bigger side, and USA food is also cheaper do to loads of subsidies and bad regulation(so, sugary, worse quality checks, but cheaper), corporation centralisation (EU is made of different countries which used to mean different food corps as well), so the grocery experience is not as relevant.