Fun fact: when cycling, I usually do at least 60km, sometimes 100 or above and I tend to already start to sweat profusely 5 minutes into any kind of workout.

Also, since I'm very heavy, I'm slow in spite of putting around 180-220 watts to the pedals throughout, so that's many hours and many liters of water, salt, and other minerals expelled with nothing coming in except for water, a couple bananas or three, and a few electrolyte tabs in one of the two water bottles I bring and frequently refill.

I guarantee you that, no matter what the "average" person of average weight with average amounts of perspiration doing an average to long duration workout needs, I DO see a significant benefit from the electrolytes compared to when I had nothing but water and bananas for the 4-8 hour rides.