system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why we're supposed to drive with one foot instead of both

(I drive an automatic, not entirely sure what the protocol is for manuals)

Anyway, when I started learning how to drive, two feet just felt completely natural to me. I mean, two feet, two pedals, makes perfect sense. I have an accelerator foot and a brake foot. Contrary to what some people may think, no, my brake foot doesn't lean on the pedal the whole time and accidentally hit it, so if that's the main argument against two-footed driving then it's a stupid one.

So what's the big deal about being supposed to drive with one foot? My dad, mum, old driving instructor and boyfriend all say/said I'm wrong for using both feet, but one-footed driving doesn't come naturally to me, and I feel like the one-foot-shift from accelerator to brake could be dangerous in situations where you have to react quickly. (I know this probably isn't the case, but that's just how it looks/feels to me)

Obviously I have nothing against one-foot drivers and know I am in a minority using both feet (I also think the toilet roll should come from behind, but that's another matter...), but I am a good driver and would like to know why I am frowned upon just for this minor detail that doesn't really seem to affect anything about how I drive.

EDIT: I realise this probably doesn't need to be explained like I'm five, but it didn't really seem to fit AskReddit.
gpt
When driving two footed, if your right foot is on the gas and you need to brake NOW, the instinct is to slam both feet down, but car engines almost always overpower car brakes, and so you will keep going, or best case slow down much more slowly than you would otherwise.

For manuals you always use the left foot for the clutch, and the right foot for the brake and gas.  Occasionally some people will do a heel-toe start where you push both the brake and the clutch with the left foot but that is a VERY niche case.  Not sure if this is reversed for right hand drive countries or not.