There is so much more then this.   I can think of a ton of digital currency that does not need to be physical... that is utter crap.  There are a ton of pump/dump alt coins out there.  I would not touch them.

Bitcoin is currently and has been like the gold of crypto currency.  It holds the most value, has the most companies going after it.  There is value behind it.  I think the value is what set's it apart.