I could say that it is not a bubble. It's a currency that is using the blockchain technology to operate, either PoW or PoS to keep the network secure, cryptocurrencies are used commonly as utilities to provide whatever services that specific platform do offer. Cryptocurrency has it's price and it is based on it's utility and marketcap, now being a bubble, technically not, it is here to last and it's the future. And still worthy to invest.