Most people didn’t have a timeframe of 100 years. More likely something like 30 or less. If there is a downturn during that time and you don’t have enough cash

Most people didn’t have a timeframe of 100 years. More likely something like 30 or less. If there is a downturn during that time and you don’t have enough cash to avoid touching your principal you can quickly have a problem. For example let’s say stocks have a downturn and you have a serious health issue it’s very possible that all your proceeds are gone and you don’t have any money to reinvest when the market goes up.