FAA was gamed, but If you think Boeing would self regulate, I think you are on a different timeline where stockholder dividends are not the prime directive.
Simply put, the definition of 'failure' of a regulation needs to be broadened. Regardless if it reduced deaths by the company itself in the near term, if it adds long term risk to deaths/accidents in the future by encouraging regulatory capture and eliminating any competition but Boeings to exist - we are worse off as a society, period. The only option we are allowing is some pseudo-market mega-corps with monopolies and the mediocrity in both service and safety or public gov run companies (which do make sense occasionally, but rarely).
There's a few solutions I can think of here which isn't "all regulation is bad" or "lets only have mega corporations in every market via poorly designed regulation" or "let gov nationalize the markets":
a) Contextual oversight. Allow a certain level of freedom at the lower tiers of markets so a future competitor to Boeing can exist and challenge them on everything from prices, to technology, customer service, and safety (which yes is a massive competitive advantage, ask all the people who now refuse to fly in Max, what other options do they have? A single European version of Boeing?). While allowing the courts to expunge any company that sacrifices on safety or any other externality via tort laws, liability, via stronger consumer and property rights.
b) Constant pressure on regulatory agencies (possibly by an outside agency) to look for regulatory capture within agencies and severely punish civil servants and companies engaged in any backroom deals, creating policy/incentives which are barriers for competition with little/zero benefit to citizens, punishing companies for obvious lapses, etc.
c) Stop politicians from anointing themselves job creators and promoters of businesses. They should strictly be in an administrative role when absolutely necessary (to eliminate any forms of violence, coercion, externalities that courts can't handle, etc). This is the biggest source of the worst of a) and b).
When politicians think their job is to 'create jobs' themselves by creating monetary/policy incentives for companies, this inherently create incentives for kickbacks to politicians and moral hazards for companies, and therefore should not be the job of politicians period. The only "help" to companies should be to help get out of the way by eliminating useless policy OR streamline necessary administrative systems. Otherwise don't help them at all.
Companies should not be able to buy success and maintain success in markets (by that I mean monetarily regardless of behaviour or outcomes) by having influence from politicians. All policy should be neutral of company size (or tiered based on size, the way modern rent control has tried to stop disincentivizing new lower income buildings by not applying to new developments) and factor in small firms who can't afford a team of lawyers or checkbox checkers.
Like most of the neoliberale 'economic theoretical models', the idea that the regulation is fully separated from the arena of the competition and thus cannot be captured and coopted is so ludicrous it begs the question how it ever became more than a joke in a b-list standup comedian's backup repertoire.
A German automaker was caught gassing the world population. They're still around, even having the audacity not to even change the brand name.