The upper class hobbies are definitely a thing. Equestrian > sailing > skiing > golf probably. Golf only being this low because it was "democratized" by muni courses and popularized first by Arnold Palmer, then by Tiger Woods.
Skiing is probably the most approachable of the activities for the upper middle class professional, but it's a $300/day activity that necessitates travel. A fairly devastating expense for many.
A $50/day activity at a local hill + a $150 initial investment (one that will last you multiple winters) in some decade-old used equipment at a local swap event.
Skiing is not cheap. But it's extremely expensive only if you have extremely expensive demands - such was wanting to ski while living in an area without hills or snow.
Ditto skiing with lift passes, travel, and lodging. Having a local hill is the exception rather than the rule tbh.
One of the takeaways I got from it was that every single upper class activity is designed to be incredibly expensive and time consuming, just because only the wealthy can maintain those form of activities. Having driveways made out of gravel, that constantly need to be redone at considerable expense, or having a yacht. Despite this, the true upper class is incredibly banal; Fussell describes them as totally uninterested in ideas, reading time and cheap disposable mysteries if they ever bother to do so. There's really a lot of Thurston Howell in them.
I think most people here would dislike how Fussell pegs liking science fiction and technology as a fairly low class activity. But it's funny how right he is, because among the upper-mids here...you hate social media in the same way, and the lower class uses it just as much.
But, oh that book is devastating. Fussell is a wonderful writer, and a keen critic.