Exercise is important in the context of cardiac deconditioning, so when managing POTS it can't be ignored.
But with that said, exercise is also recognised by most in this field as a key trigger for worsening of symptoms & autonomic function. Its definitely not considered a harmless thing that can just be ramped up against patient objections, as per ME/CFS GET nonsense.
POTS practical guidelines I've read recently make it clear exercise has to be highly tailored and is advised only when tolerated. The approach is to try and find ways to make the exercise tolerable, rather than assume everyone can do it if they just try hard enough. For example, medication usually comes first, which may then offer increased exercise tolerance. Basically a common-sense approach that doesn't assume anything.
Its worth remembering POTS captures a wide range of underlying causes, the treatment advice for an elite athlete experiencing post-concussive POTS will be very different to a patient that may have some type of autoimmune mediated SFN underlying POTS. But regardless, when it comes to exertion intolerance the focus is on understanding what's happening physiologically rather than any assumption that we're just exercise avoidant.
I see a couple of experts in the UK, both aware of my CFS diagnosis and they have never tried to encourage me to exercise - they actually urged caution when I quizzed them about what they'd recommend.