Reduced/Low risk is key.
One of the key principles of this strategy is that average levels of returns can be achieved whilst running with relatively lower risk.
Over recent years (at least in the UK), we've seen markets fall by 50% in value. To restore that 50% loss requires a 100% gain.
By limiting potential downside risks to single digits, recovery is so much simpler and more rapid.
For those who have experienced 50% declines, it may take a decade or two to recover to their original starting level investment, let alone catch up with anyone who just starting off at that higher level.
I can assure you that with good money management, reduced risks and potential gains comparable or exceeding the average you can certainly sleep alot better than many others at present.