OP, is your only experience working with technology companies and trendy startups trying to hit some mega-million valuation?
The real world is a lot more messy than the best practices that tech companies come up with. Go work for some local warehouse or AC repair company's IT departments. They might have some technology for managing inventory or scheduling appointments or billing or any one of a hundred tasks that isn't done in the most modern way.
There's many industries where technology isn't valued or emphasized and that are still using code and some practices from 10-15+ years ago due to financial constraints. And that's fine, as long as it works and is secure. Many times it isn't, but it can work just fine even if it doesn't look modern.
I'd bet the vast majority of websites out there are not using containers today.
I'd bet there's some pretty big and profitable websites out there that probably deploy stuff via uploading a bunch of files via SFTP (or even FTP) and perhaps running some deployment script that's been hacked together a decade ago.
Hell, we talk a lot about the market being consumed by React and languages like Python. But jQuery is still ridiculously widely used. PHP is basically persona non-grata on HN, but its market share among overall websites is still pretty high.
I'm kind of mad that the community here killed codevark's answer because that's an example of the messy world we live in that gives a partial answer to OP's question.