Just makes them more grippy. If the pedals were totally flat your foot would slip off, especially in the wet and mud. It’s good to use a stiff soled shoe too as otherwise the pins will just shred the soles
Like with anything, you pay more for better quality. A bit like sports cars, bikes go up in price when you start making them lighter, using carbon, magnesium and titanium components etc. But yeah at the end of the day it’s a bike and it can only get so technical. A £5k bike probably has around £1k worth of components on it, so the buy new price is always masssively inflated. Those pedals I just bought were £100 new when they came out. I picked that pair up for £20 on eBay.
Them bikes are just gay. They have cock shaped seats that the owners rub oil into and spend the next 40 miles of peddling rubbing their **** hole all over it trying to get some sort of pleasure. It probably costs much less to ship an African twink over in a crate who'll rim you for a jam sandwich every day for the rest of his life.