It only gets you 2-3 miles of range per hour. The other challenge is when you are traveling it's not like there are outlets everywhere that you want to charge, so if you want to get 5-10 miles range in your car you would need to wait a few hours. There are definitely other charging options aside from superchargers, but the premise of owning a Tesla is to have the fast wall connector and leave the house with a full or near full charge during the day; When I had my Model X I would not even plug it in and could go a week or so without charging it; but everyone is different, some people drive to work an hour each day; for them, it would make sense to charge overnight. For reference here is the link to the charging speeds on Tesla's website.
Charging Your Tesla