I think all three of these points, but especially the first two are rather speculative; I don't personally believe they hold, though I can't be sure.

Most quality defects I see are ultimately down to culture, not training and certainly not certification. Getting to excellent quality simply does not require great training nor rigorous certification, and I'm not even sure it really benefits from either all that much. But what it does require is a culture of chasing down all the avoidable risks, to fix not just the immediate bug, but also the process that allowed it to come to be, to pre-emptively look for whole classes of bugs or misfeatures seriously, and to always look deeper than for underlying causes or interactions (i.e. take the 5-why's game seriously).

It's perhaps almost a trope by this point, but it's still a great reminder and example - sqlite. About a month ago Richard Hipp, one of the primary authors, gave a great presentation "Reliability Lessons From SQLite" (https://youtu.be/V_qzqY1bb7I) - and notably, I'm not seeing even _echos_ of training and certification in their clearly world-class process. I don't think you can even seriously claim it's all that expensive, if you consider how tiny that team is, and yet how much they've achieved.

If larger organizations fail to achieve high quality - well, _why?_ It's not due to lack of training, certifications or smart people. Perhaps its intrinsic about larger for-profit corporations, but I suspect we could do better with better incentives, and a more serious attitude about dealing with mis-aligned incentives throughout our culture. Is it really a flaw for a corporation to prioritize short term cost reduction even over long term self-harm if that's what they're judged by? Is it a flaw for a profit seeking corporation to largely ignore costs their low quality imposes on others? Is it a flaw for a for-profit organization to take huge risks when the upside is unbounded but the downside is mere bankruptcy without any further liability?

I don't know how to solve these problems, and don't want to claim it's even remotely reasonable to throw out the capitalist baby with the corporate bathwater, but surely we can do better than the status quo even without a revolution. Misaligned incentives and tragedies of the commons aren't new issues, nor ones without potential mitigations. We're just choosing to ignore those inefficiencies, and have for decades. And at this point, even small changes in incentives might have truly wrenching consequences; the ingrained and by now deeply embedded carelessness in our huge software and other engineering stack is corroded at every level.

TLDR: I don't have the answer, but I'm pretty positive it's not an issue of cost, training or certification.