The way to fix it is to empower one government agency to do aggressive pentesting against every other agency, hospitals, banks, infrastructure, and big corporations, with salaries matching the private sector. Impose a legally-enforced deadline to fix any issues, with a fine (for private actors) or demotion of the guy in charge of infosec (for state agencies).
Forget compliance checklists, KPMG "audits" and all that crap, just have government-sponsored hackers trying to get into everything like an attacker would.
France seems to have had a ton of government hacks in the past year at various levels, so it's sorely needed.