Let's say, playing it safe means preferring to buy Bitcoin rather than altcoins.. that means the risk borne is smaller because Bitcoin's volatility is not as crazy as altcoins.. so it can be said that buying Bitcoin is one of the safe investments for the long term.. even though you will see your assets sometimes minus due to corrections, but for long-term projections, Bitcoin will still be profitable.
The size of the profit in the investment you make, of course depends on the money you spend and the assets you buy, even I feel safe investing in Bitcoin, provides no small profit.