I have not seen it here in the US but in many other countries you can see the statues of Saints or Mary with silver/gold medals, precious rosaries or gold chains. Also specially for the Virgin you find very elaborate mantillas, dresses, etc. These are the testament of a prayer answered by that Saint.
Also if people don’t come forward and testify to the Church that their ailment was cured by a miracle from the intercession of a Saint, the Church would not have what is needed to advance the Canonization process for the Saints today given the process She has instituted to proclaim them now.
Peace!