I can’t speak for everyone else. For some, yes it is the pleasure of living vicariously through a model, for others it’s doing side stuff with them. For some it could also be a tax write off, yes. Maybe they have a special relationship with the model they hired and they are more friends? I don’t know.
There’s a whole list of reasons why someone would hire a model, and not have actual anal with them. Especially a Bel Ami or other famous model. For example, I’m sure a lot of people would pay just to meet someone like Paul Cassidy and not even do sexual stuff with him just so they can be in his orbit. There are people on here who would pay famous models to hang out with them in Prague.
To each their own, it’s their money…