17th iteration in less than 20 years, billions produced. About a billion already 'obsolete'. Seems fair to ask: what's the expected lifespan of an iPhone these

17th iteration in less than 20 years, billions produced. About a billion already 'obsolete'. Seems fair to ask: what's the expected lifespan of an iPhone these days? Does anyone here have insight as to what percent of materials used to make them is actually recycled?