"My grace is enough for you: for power is perfected in weakness." - 2 Corinthians 12:9Not everyone is healed - at least not right away - some are left with their disabilities, some for all of their life. Catholicism doesn't preach a prosperity gospel.
At Fatima, Lucia asked Our Lady to cure some people who were ill, Our Lady told her some would be healed, others not - explaining that Our Lord did not trust them. I understood that to mean they would not be faithful if they were all patched up and made 'normal' again. Nevertheless, she told Lucia that they should pray the Rosary every day.
Of course, in other cases, Our Lord may simply want us to share in his sufferings and witness to the Gospel:
"Those who are well do not need a physician, but the sick do." - Matthew 9: 9-13
In order to learn the meaning of the words: It is mercy I desire, not sacrifice. I did not come to call the righteous, but sinners.
Works for me.