Somehow people are going to need to get their hair cut, so this isn't going to be a horse liveries situation. More people may sacrifice quality or preference for a specific style & do it themselves. Some people might get shorter haircuts so they don't need one as often, maybe trim thing around the edges in between paid haircuts. Some people will be price elastic and pay higher prices.
The economics and behaviors may change, but the need won't go away.
The economics and behaviors may change, but the need won't go away.