Back in the 80’s when dressage was just starting to be an “in” thing to do, there were some very nice “all purpose” saddles made that looked like a hunt seat saddle, but were balanced more for dressage, in that the most comfortable position for the rider was with the rider’s back at a right angle to the horse’s back, not up to 15 degrees in front of the vertical, which is the usual hunt seat position. However, these saddles had enough knee roll to be comfortable & safe for some jumping. In the smaller sizes, they were excellent for riders with shorter legs or children because the flaps were short enough that the rider’s feet were below the end of the saddle flaps, which can be an issue in a standard dressage saddle, which typically assumes that all people wishing to do dressage have elegantly long legs. I still have 2 of these saddles. In the late 90’s, Classic Saddlery had a line of saddles similar to these developed and sold them across the US, and I also have one of these. These were genuine “all purpose” saddles, although if one got beyond small jumps, one would obviously want a saddle specifically designed for jumping. But for beginners and people still exploring which discipline they wanted to be their main riding style, they worked fine. And they were at least “multi-purpose”, in not “all purpose”, as most riders ended up getting a saddle designed for a specific purpose, once they determined what that would be, and if they were into something like 3-day eventing, they would have a saddle specifically for each phase. There are still some of these saddles floating around in the used market, but as has been pointed out, a saddle must fit both the horse & the rider equally well to be a good choice.