Same reason why we have different USB ports (normal, micro, mini, etc). Designs keep evolving. Also, I think the weight of phone is very important so anything

Same reason why we have different USB ports (normal, micro, mini, etc). Designs keep evolving. Also, I think the weight of phone is very important so anything to shave even a few micrograms off it could be one of the reasons (Read: Why Steve jobs tossed the first iPad in an aquarium [1]) Lastly, i think it is also because of what you said, especially with the new closed walled phones where the device manufacturer (read Apple) would like to seal you into a contract with the phone company and phone. [1] https://my.news.yahoo.com/steve-jobs-dropped-first-ipod-152100470.html https://my.news.yahoo.com/steve-jobs-dropped-first-ipod-1521...