What is the benefit of asking and supplicating to Allah and striving, since Allah's decree is what will come to pass, especially in the الاستخارة prayer?

Allah Almighty has made supplication a means of attaining what is desired. It is one of the means by which a servant gains Allah’s forgiveness, mercy, and sustenance. Allah Almighty has ordained many decrees to be contingent upon one's supplication and asking. The desired outcome does not occur without its cause, which is supplication, in addition to sensory causes. Supplication repels divine decree, and nothing repels divine decree except supplication. For example, the healing of a sick person through supplication is Allah’s decree that healing will occur through this supplication. When a Muslim regards istikhara (seeking guidance) and supplication as a means of attaining what is desired, he will not neglect it.