This is a ELI5 response with a high school understanding of human biology. Hangovers are from alcohol poisoning (variable levels), and this poison is detoxified by your liver. The waste is either sent to the kidneys to be processed as urine or to the bowels. Your kidneys require water and minerals to process this waste, and water is the vehicle for excreting waste through urine. When you drink all water and no vitamins/minerals, you risk depleting your supply of those essential elements. So, assuming your water has an appropriate balance of those things, I would think that water with electrolytes or minerals is better than plain water at helping your body process and detoxify alcohol.
Tl;Dr: water with balanced electrolytes/minerals > plain water for hangovers.
This is a ELI5 response with a high school understanding of human biology. Hangovers are from alcohol poisoning (variable levels), and this poison is detoxified by your liver. The waste is either sent to the kidneys to be processed as urine or to the bowels. Your kidneys require water and minerals to process this waste, and water is the vehicle for excreting waste through urine. When you drink all water and no vitamins/minerals, you risk depleting your supply of those essential elements. So, assuming your water has an appropriate balance of those things, I would think that water with electrolytes or minerals is better than plain water at helping your body process and detoxify alcohol.
Tl;Dr: water with balanced electrolytes/minerals > plain water for hangovers.