Only those who invest what they can't afford would be scared of volatility and the reason for DCA a method is for investors to just only buy the amount of Bitcoin that they afford, this helps in accumulating bitcoin without any stress and with this method of investing their is no need to be scared of the volatility of the market because you are not expecting profit in a short time. DCA method of investing is a longterm investment which you don't have any business of volatility for profit so soon, you only just take advantage of the dip whenever you come across it because it is also a good opportunity for investors to but during the dip. DCA method of investment is all about buying bitcoin at the rate which you can afford and no need for fear of volatility because it is not an investment one is depending to make profit very quick .
Investing in bitcoin the right way by buying it regularly with a DCA strategy. Adjusting cash flow properly, emergency funds, reserve funds and funds for execution. I think no one is afraid to invest in bitcoin but because they don't plan well they are not consistent in investing.
I also agree with you, we can set aside monthly income to invest in bitcoin, invest with money that we don't use for our daily needs. The important thing is that we must understand that investing in bitcoin is not for the short term but for the long term, so there are many periods that we will go through each year to buy Bitcoin.
Buying Bitcoin can be done through a trusted Exchange and withdrawing it to a personal wallet to be held in the long term.