According to CoinMarketCap charts it is Bitcoin which is creating the bear market
Looking at the total market cap for all crypto excluding Bitcoin we find that the marketcap has been relatively stable. In Sept 2017 we saw a market cap of around 74 billion. In Sept of 2018 we saw a market cap of around 86 billion. On Nov 4th the market cap was over 100 billion for "altcoins". But after the Bitcoin Cash fiasco the market cap is now around 57 billion.
This indicates that the sooner there is a decoupling from the dependency on the ascendancy of Bitcoin the better off the crypto market could be. If Bitcoin is in a bear market it depresses the prices of all the other cryptos because Bitcoin dominance is going up and then it's being used to manipulate the entire market. That being said even during this, for the most part alt cryptos did seem to be growing in 2017-2018. and from 2018-2019. Bitcoin seems to be in the decline until 2020 when the next block reward halving comes.
How could the next block reward halving affect the decline of Bitcoin?
I agree that the crypto market as a whole will be better off once there is less correlation between BTC prices and all the alts. Coinbase and other gateways, which allow going from coin to fiat, might help as they add more crypto/fiat pairs.