Rich countries have an obligation to reduce global inequality—they accumulated wealth partly through colonial extraction and trade advantages that developing nations never had. Mandatory aid targets would save millions of lives from preventable poverty and disease while costing wealthy nations less than 1% of their GDP. When some people have more than they can spend while others die from lack of clean water, charity isn't enough—it has to be a structural requirement.
Forced wealth redistribution punishes successful economies and removes the incentive for developing countries to build their own institutions and economies. Aid often gets corrupted by local elites instead of reaching people who need it, so the problem isn't how much money is given but governance in receiving countries. Nations should be free to set their own fiscal priorities—voters didn't elect their governments to send tax money abroad, and that responsibility starts at home.