Many neurological diseases and conditions cannot be reversed in 1-2 days. Full recovery is usually a longer process, taking several months! During this time, you cannot be kept in hospital.
When you are discharged from hospital after an acute episode of stroke or peripheral paralysis, it does not mean you are cured, it means you have done the hard part and need to finish the rest at home. It can take years to recover from paralysis due to stroke and to relearn movement, and even longer for a peripheral nerve injury!
If you don't continue with your treatment after a few sessions of physiotherapy, electrotherapy, etc. in hospital, you will not recover. If you want to recover completely, you must continue the exercise and treatments at home.