My assumption has been that trams are the only lifts that can handle very long spans between towers, and are also more wind resistant. The Alps have a lot more of that topography than North American ski areas. And sightseeing is a much higher component of revenue in the Alps, like Palm Springs here, which is essentially all sightseeing.
I do not know if 3S gondolas can handle as long spans between towers as trams. However, I've been on enough 3S in the Alps to agree with ChrisC that a 3S would surely have been feasible at Jackson Hole. And unlike Snowbird, the tram is the only way to the top and thus still a chokepoint with big lines.
The Snowbird tram is practically redundant.
Not until Peruvian was built in 2007. Nonetheless the Snowbird tram has been essentially replaced: track cables in 2016, cabins, drive system, motors, braking systems, and bullwheels in 2022. That span between towers over the Cirque is very long, possibly too long for a gondola.
Heavenly - Not sure why their tram was built. Assume summer tourism to view Lake Tahoe and grab food/drink.
Yes, and it dates to the 1960's, when the alternative was a slow double chair up Gunbarrel. The Stateline gondola opened in 2001.
Big Sky / Lone Peak - Iconic. No other design would really work but a tram.
Yes, the long span issue again.
It was obvious when I was there (not in ski season) that the Cannon tram was primarily a sightseeing lift. I'm not sure about Jay. Wind resistance?