This site's own framing is direct: instead of leaning on caffeine or a single ingredient, it takes a complete approach across five mechanism fronts.
This site states that no single ingredient does all the work — six ingredients address five distinct fronts: memory, focus, brain-cell health, mental energy and oxidative defense, rather than one ingredient attempting all five.
Worth noting this is a design-philosophy explanation, not a claim that six ingredients are clinically proven superior to one — this site is separately direct that its citations concern individual ingredients, not the finished combined formula.