It already has. It's the internet. Sex crimes go down when internet access goes up. It hasn't 'replaced' it 100% but that's the point with a lot of this stuff it is slowly reducing jobs without creating new ones.

I really don't think it'd be impossible to create a machine that cuts hair. Or making coloring hair at home/in salons easier.

Even if it's augmented by a human if it's 50% more efficient there might go half the jobs. Use robots so the staff need little to no training. Hair cuts would be cheaper so demand would go up, but jobs will still go.

In a failing economy paying to have your hair cut is an unnecessary expense. Things can start to fall pretty quick.