Average male over 30 can dilate their pupil to around 6mm, the maximum amount of light gathering a typical male's eye can absorb.
1-8x24mm optic would let it maximum light at 4x magnification in twilight. Lowering it to 3x, or 2x, or 1x will not allow any further light be absorbed.
So for the contrarian minded that demand more light gathering for this mythical night-time daliance with chupacabras and sniping bats, whats that look like? Well if you buy 2-10x40mm optic, yes, you'd actually be able to get max light absorption at 5.75x and below. But at a consequence of taller rings, slower target acquisition, and more perceived recoil as your face comes off the comb more. But why stop there in our hypothetical? Lets go fall-on monster trucking loving redneck mode and get ourselves a 3-15x52mm chunk of glass? Yes, you could theoretically have your optic set at 8.66x and get full light transmission at night.
Who are these night hunters that are so rich they are buying gigantic glass, but so poor they can't buy a night vision or thermal instead? How is it that they require this light gathering ability, yet their game of preference is willing to sit around for them to fidget with their scope extensively while the shooter attempts to find proper eye adjustment in pitch black to look through their scope? And who is this entourage of assistants with the world's most powerful highbeam flashlights that are able to project enough lumens at great distances to shine an animal that needs to be seen at 5.75x to 8.66x magnification hundreds of yards away?
Light gathering is a myth for people that want huge scopes, even though huge scopes are slow to acquire game and result in more recoil and more lost game due to failure to rapidly acquire target.