Why did God not answer the prayer of the distressed for increased intelligence and the ability to devote himself to seeking Islamic knowledge, even though learning religion is essential?

One must learn the individual religious obligations (fard al-ayn) from the Sharia sciences. Anything beyond that is supererogatory. A person can benefit themselves and the Muslims by directing their energies towards what they excel at, if they are unable to achieve prominence in the Sharia sciences. A Muslim should be keen on what benefits them. After learning the obligatory, they should then consider what they are good at and pursue it with the intention of doing good and benefiting Muslims. As for the non-responsiveness of supplication (dua), Allah is not to be questioned about what He does, and He knows best what is in the interest of His servants. The servant must entrust their affairs to Him and be content with His decree, while also taking the necessary means. Supplication never lacks benefit: either it is answered, or an evil is averted because of it, or it is stored for the Hereafter.