I used to use straight water, and eat my carbs and electrolytes. However as I got more serious and faster riding it was just easier to put it all in my bottles. I do for 60 mile plus rides take a few snacks like a box of raisins or a granola bar or similar. But many times I finish those rides never touching the snacks.

Powdered mixes with carbs and electrolytes are easy to carry in a back pocket and replenish a bottle with when you get to a water source.