1. Allah listens to our duaas and will answer them if made sincerely, but sometimes what we think is good may actually be bad for us due to our limited perception.
2. People who pray to others besides Allah are actually only praying to Allah as none but Him have any power, but He may test people by fulfilling some duaas to misguide them into shirk.
3. Our duaas may not be accepted if we show impatience, earn unlawful provisions, or fail to enjoin good and forbid evil. We should only seek help from Allah with full trust that He knows best.