> I'm sure you can configure whatever language server PHP is using to disable specific warnings, etc

You may be able to do this by editing a language server-specific config file in whatever arcane syntax they decided to offer. But there isn't any editor support for configuring languages servers, so it's a bit of a lift for a newcomer who just wants to turn off some warnings

I think the application should own its dependencies and its default config. In this case, it felt to me like no one had really looked at them.

Editors should take full responsibility of the user experience. The user should not have to care about the existence of language servers.