While I agree that in most Instances, an Intra-Workout Drink isn't necessary.
I Personally have been using one since around 2010.
Because my Workouts are Extremely Intense, and will sometimes go on for over an Hour when On-Cycle.
And I do notice a difference in Performance with my Intra-Workout, as apposed to without...................................... JP
P.S.
But I don't use any Special Intra-Workout brand.
I use 1/3 of a Post-Workout, that's only Whey Hydrolysate/Maltodextrin/Creatine/Taurine/L-Leucine/and Leucine Peptides.