As CR says, paper hearings are not without any success, but usually only when (a) there is fairly conclusive evidence that the decision was wrong (and here I mean medical evidence that has specific bearing on the descriptors); or (b) the decision relates to a legal point and not one relating to the claimant's health compared with the descriptors.
In general though I recommend nearly all my clients to attend the hearings, as there is little evidence better than your own version of events.
I recognise that this is no small ask to make of a lot of claimants, as the very nature of their entitlement to benefit makes this kind of event more difficult than for most people, but in spite of this I still recommend it.
What's your situation? Does the decision relate to illness? Have you got evidence?