To support the "you can get pretty far in playgrounds on an iPad" assertion, one of my coworkers built something like half of a language flash card app on his ipad before he transferred it over to his laptop to finish it. I thought he was nuts doing dev on a tablet, but he said it was actually a really nice dev environment and in some areas it totally outclassed xcode. Swift may not be your favorite language but it is an objectively good modern language compared to a lot of what's out there in industry, and its skills are easily transferable to several other good modern languages that are becoming popular.