Bitcoin price hit $20,000 and eth now is about $600. Where is the value of a coin from? Technically, cryptocurrency has the value but today there are thousands coins and tokens. Why some are good and other are not? The value of a coin is from the community. The community includes developers, miners, masternodes, traders, stakers, hodlers, merchants and other supporters. The bigger the community, the higher the value of a coin. 

Let's give example of ethereum. Ethereum with smart contracts has created hundreds of communities. The communities bring the token to other platfroms. Other platforms make collaboration with the token developers. In this relationship and activities, the demand of a token will increase so the value or the price of the token will increase too. 

CAN CRYPTOCURRENCY WITHOUT COMMUNITY?

It is impossible. Cryptocurrency is community currency. The community accept the coin as the payment system. That is why the bigger of the community, the better of the coins. Bitcoin community start from small circle of developers then grow after bitcoin faucet was launched.

The first-ever Bitcoin faucet was called exactly that - The Bitcoin Faucet - and was released for public use back in 2010 - one year after the inception of Bitcoin itself. It was created by a man named Gavin Andresen, who is currently known for being heavily involved in cryptocurrencies, especially Bitcoin.
Bitcoin faucet / bitdegree tutorial 

Launching of bitcoin faucet had spread bitcoin to wide users. Now, the way to create community , some developers give airdrop, bounty jobs and give away. Those are ways to enlarge community of the new coins.

Cryptocurrency without community will loose its value sooner or later. When public see that there is only few wallet holders, they will think twice to buy or use the coin. It will effect to coin's demand in the market. When the demand is low, it will effect to the drop of the price.