What is the solution for investing a small amount of money given a 3% profit margin and a 2.5% zakat rate, and the insecurity of operating money outside the bank?

"Forbidden doors, such as usury, do not become permissible even if they become widespread. The Messenger of Allah (peace and blessings be upon him) said: 'Usury, even if it increases, its outcome will be a decrease.' It is deprived of blessing, and a cause for divine wrath and punishments. Allah tests His servants to distinguish the wicked from the good. Therefore, you must balance between this fleeting world and the eternal Hereafter. Do not be deceived by the multitude of those who perish, for patience in upholding religion in these times is like grasping a burning coal. Dealing with usurious banks is among the most severe prohibitions, and its perpetrator is cursed, waging war against Allah and His Messenger. Piety towards Allah expands one's provisions and leads to a better outcome, as Allah Almighty said: 'And whoever fears Allah - He will make for him a way out, and will provide for him from where he does not expect.' Likewise, whoever abandons something for the sake of Allah, Allah will compensate him with something better."