Soft flex boots (rated 1–3 on the stiffness scale) are a great match for two types of riders: beginners and dedicated park or freestyle riders. The very pliable construction gives you maximum ankle mobility, making these boots comfortable right out of the box with minimal break-in time.
For beginners, soft boots are forgiving—you won't fight your equipment while learning to link turns and find your balance. They let you develop proper technique without the fatigue that stiffer boots can cause early on. For park riders, that same flexibility makes presses, butters, and tweaked grabs much easier because your ankles can move naturally with the trick.
The trade-off is less edge-to-edge precision and stability at high speeds. If you're charging steep freeride lines or riding fast on groomers, you'll want something stiffer. Heavier riders may also find soft boots don't provide enough support, even for park riding.