No its not a bubble.Any asset or stock which is over valued than its true value only could be termed as a bubble.I hope that bitcoin is not over valued.Also,bitcoin.is not only an asset as it is considered nowadays.It is.also used as a currency but mostly in Japan Where it has been legalized.But most bigger co companies like amazon are in an idea to accept bitcoin.Also,traders regularly buy and sell bitcoins thus the demand would continuously remain.So.bitcoin is not surely a bubble.
Too thin of an analysis especially when the technical cap balloons the transaction fees and BTC can't be efficiently used to make small purchases. There is a need for a decentralized currency created by the market and not by the government and a lot of people give a lot of value a trust to Bitcoin but this value and trust could mostly shift to BCH or an other crypto.