its main purpose is for dripping. it gets rid of the extra hardware in the atomizer and results in a better, more flavorful vapor. the bridge's main function is to deliver the
juice from the cartridge down into the coil in a controlled manner. but its not a bulletproof concept. dripping IMO seems to be the most consistent method, but requires much more work to accomplish (i have to put a drop in every 4-6 draws, while a cartridge can go for 4-5 times as long before needing a refill). its basically a trade off between efficiency and consistency for me.
i still have some bridged attys that i use with carts. but not nearly as much as i drip. they both have their place.