There is nothing wrong with keeping our coin on exchanges especially if it is a little percent of our portfolio, maybe for the sake of trading it with other coin pairs it swapping it to altcoins to make more money.
I'm sure there are still some people who leave Bitcoin on exchanges. but maybe their needs are different. if the goal is long term, of course, it would not be a good idea to keep it on the exchange. and perhaps the problem of transaction costs which are sometimes very inflated could be the reason if you are a trader.
However, exchanges are not the best place to store Bitcoins. Even though saving in your wallet still has risks, we still have to choose the smallest risk. we never know what disaster will come to us.
Having other sources of income will help you to endure through out the bear run, because the price of BTC will be dumping to make people BTC in their wallets to lose value at the moment, but if you have other sources of income, it will help you not to sell in the bear run than to wait for the bull run before you can sell.
having other income would be good and it could protect our Bitcoin investment from being disturbed by the urgent needs that Bitcoin holders often experience.
but I think there is no need to be fanatical when our thinking is profit. investors understand Bitcoin market patterns. when we can profit when it pumps, why should we survive when it dumps? unless there is a planned time frame for it to be achieved. and the issue of pump or dump prices will not be considered at any given time.