Suburban America is dying because it is operating like a Ponzi scheme: the property taxes aren't high enough to pay for the long-term maintenance and replacement of infra, and for the past handful of decades it has compensated by filling the budget holes with one-off windfalls due to taxes on new development.

This house of cards obviously falls down when expansion ever slows down. The only solution is to raise the property taxes per yard of road, but that means low-density housing becomes unaffordable, which would force towns to increase density by building things like row houses and apartment buildings.

Solar is in a completely different position, as the solar itself is profitable. There will be no shortage of cash to replace it, only perhaps a shortage of labor. But solar doesn't really have a fixed lifetime and will happily operate a few years longer, and due to its highly distributed nature it doesn't require a risky all-at-once replacement like the Boston Big Dig either.

The global solar rollout is going slow enough that it won't be finished before the first units will reach the end of their economical lifespan. I reckon it'll just shift into ongoing maintenance as time goes on.