I think the point is that you can do both. Sometimes being able to yeet a PHP file to some PHP/wordpress hoster and get a project done in an afternoon is exactly what is needed, because even spending 2 or 3 days to set up a proper CI and deployment environment would be too much friction.

There is a whole range of projects like that out in the wild, once you leave the realms of startups and big tech.

It's about as easy to do "proper" deployment using bundles / containers / CICD / kubernetes / gitops with PHP as with any other stack. It's also possible to click a wordpress domain for $10/month and upload 2 php files and start making revenue.

For a small business that is starting up, choosing between $10k of freelance work to get a nice github actions workflow on GKE + a monthly retainer of $2k for "maintenance" vs a one time $1k of freelance work to get a wordpress where you can configure the plugins and theme yourself is a no brainer. Many of those small business then grow much larger and reach a point where in hindsight you can say "should have gone with docker containers". But the original decision was not just perfectly valid, but probably the only reasonable one.