The fact that balcony solar has such short payback periods really emphasizes the scale of the failure. Why can't utility scale operators use bulk purchases of the exact same panels, in a more optimal installation (south facing, unshaded etc) to achieve similar or better payback periods?
Balcony solar is a whole lot like Uber, a way to side step onerous regulators, landlords that won't permit/invest in rooftop installations, planning approvals, transmission bottlenecks (eg. SuedLink [1] being forced to use underground cables) etc. The German government tolerates it because it keeps voters happy and helps reduce dependence on foreign gas.
At the end of the day though balcony solar is better than nothing, so let's not let perfect be the enemy of the good.