Sure the monopoly made sense when it was issued, but once tech catches up to the point of making it obsolete, the incumbent rarely goes down without a fight, delaying the deployment of new technologies, ultimately hurting consumers.
I'm not in California, but sounds to me like PG&E maximized profits by reducing maintenance, then when they were really far behind and running into issues, they begged for more money from taxpayers because they could not afford to make up for years of maximizing shareholder and senior management profits... I.e. corporate welfare.. they made lots of profit knowing this would bite them in the rear end, and then want the government to bail them out. It's nearly always win-win when you're that large of a company to pull these shenanigans
A non-profit government-run utility wouldn't have a profit incentive to skimp on equipment maintenance for decades. It would have other, more interesting problems.
They were running bootleg copies of Windows as recently as 2015 because they don't have the resources or incentives to upgrade.
Every office of the executive executive branch is in theory non/not-for-profit but they still manage to waste as much money if not more than a comparable private sector firm.
Federal light and power would not go well.