False. You're forgetting that Bitcoin is also a software system that allows ledger transactions to be sent and validated with no central authority. THAT in itself is a huge achievement, and provides a great deal of that "purpose" you seek.  It's easy to confuse these things, of course, because Bitcoin is the name for both the software system and the currency used in that software system. The two should be understood separately, and the latter derives its original value from the former, and it's long-term value from the supply and demand of that original value. Make sense? =)

Gold and silver have use as jewlery and in industrial purposes. Bitcoin has use as a recording and validation mechanism for transactions.  Gold, silver, and Bitcoin all additionally have value as monetary instruments due to their properties.