One should be at the bottom one at the top. I understand space on the phone is a premium but a second port would make the phone so much more usable. Wired headphones, flash drives, camera modules, speaker modules, keyboards, even connection to a TV, all could be used while charging. It’s a shame it’s not a thing, USB is extremely versatile port, but you only get one and it’s used for charging half of the time. (I am aware dongles exist)
Well, it depends what you imagine “general purpose computing” is. Android OS is primarily targeted at phones, with specific set of requirements, so I don’t think it can ever match desktop OSes, without major sacrifices from the both worlds.
The main reason why Android cannot work as a general computing OS are the many barriers and restrictions it has compared to traditional desktop operating systems.
Linux for example, which Android is based on, works fine* on the desktop but also on tablets or phones.
*as in most modern apps scale properly and are usable on the desktop, tablet or phone. Support for the hardware, especially on phones and tablets, varies greatly.