all cryptocurrencies users definitely need altcoins because altcoins have various functions to use. in addition to trading in various markets, altcoins have certain functions that are in accordance with the purpose of creation and development that occurs today and in the future. and altcoins are also needed as investment tools because many altcoins have good enough potential to be used as long-term investments.
Other than bitcoin it is possible to see selected number of altcoins having its purpose. Apart from those coins, majority doesn't have anything specific. But, the trading keeps the volume and helps with the growth and decline of the market. Whenever there is more disturbance in the market, suddenly people get into fear if there is only one cryptocurrency. This is being removed with more number of cryptocurrencies available in the market.