Any success is granted to us by Allah (SWT) but it is linked with our hard work and sincere efforts with out which no success can be acheived. Worldly success can be a reward and bounty for the believers , and it can be a test and examination as well.
It is very wrong to think that worldly success is just because of our efforts with out the help of Allah (SWT). This is the wrong logic of Qaroon ( Korah) who said: (Whatever I have is because of my knowledge (قال إنما أوتيته تلى علم عندي)( Sura Al-Qasas: 78).
Allah (SWT) says in Quran(16:14): Whatever bounties you have is from Allah).
Hard work is a condition to get the success by the help of Allah (SWT).