My observations and conjecture from very limited experience --
1. European areas are well connected to the rest of the basic infrastructure. They are closer to population centers and port cities. This means the logistics of power, water, food, etc are all reduced. Railroads up to the mountains. Jobs are available nearby for offseason. Also, easier to get to resorts in general and so the 'captive audience' factor you have in US is not present.
2. Monopolies/one big company vs. many small operators. Negotiating power for the lift operator is much reduced.
3. Piste vs. off piste and liability. Rescue by patrol in US is foregone conclusion regardless of injury location, but in Europe you opt into specific insurance for off piste rescue. Furthermore, if you cause an issue offpiste (avalanche) you are personally responsible.
4. Much fewer staff on the mountain in general in Europe. If you want a guide, you pay for one separately. They don't hand hold you in Europe like in US. Signage in general is worse - the ski experience is not as customer oriented in Europe.
5. Guides/lessons etc are a separate expense and again not part of a 'resort.' More competition here again and if its a bad year for lessons, those companies just fail. The lift operators are not exposed to that risk.
Who pays for snowmaking in Europe? What about big lift projects? Is any of that state funded in Europe? Would love to see a full study on why specifically the day lift tickets are 25%-40% of the cost seen in US. Quick search shows that season pass prices are comparable.