Is it permissible to wish for death due to the hardships of this world, and what is the ruling on that in Islamic law, and does wishing for that constitute disbelief?

Prohibition of wishing for death, and that a long life spent in obedience to Allah is better for the Muslim. The believer loves a long life to increase in goodness, elevate in rank, and multiply rewards, and the torment of the Hereafter is more severe and everlasting. There is no way to remove hardships and worries except by turning to Allah, adhering to His law, striving in His worship, drawing closer to Him, and supplicating to Him. This is the path to a good life in this world and the Hereafter, as Allah the Almighty says: ﴿Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life, and We will surely give them their reward [in the Hereafter] according to the best of what they used to do.﴾ [An-Nahl:97].