Withdrawing Bitcoin from Coinbase does not mean not using Coinbase as a marketplace to trade Bitcoin or Altcoin. The negative information about Coinbase recently has been very sensational and detrimental to Coinbase, I am sure that Coinbase will not do anything that will harm it.
For me, all exchanges have the same uses and benefits, it's just that if you want your Bitcoin and Altcoin to be safe, it is better to move all coins to a personal wallet that we have after doing various activities on a centralized exchange.