The best birth control method (as defined by least side effects and max efficacy) I’ve come across is cycle tracking / family planning (called that because you can use it to get pregnant as well as prevent pregnancy). It’s simple (you can only get pregnant at certain times in your cycle), but there’s nothing for pharma to sell (it’s free!). Weirdly, doctors never seem to trust women to go through with it (and always try to push medicated birth control), but it’s easy, even before Apple added it to their products.