I agree on the "just work" principle, but stuff like "docker compose" is easy enough to use, and "standard enough". Typing "docker compose up -d" once isn't that much effort. And make sure the connection string is configurable through an environment variable so people can use $something_else if they really want/need to.
Practicality beats purity, and all of that. Especially when it saves quite of complexity in the code itself – new contributors are going to struggle with that, too.
The problem with this attitude (and please don't take this as a personal attack) is once a few people with this attitude come through a codebase and make their "practicality" compromises, the codebase devolves into mediocrity.
For a little more context, I work on dev tools for an org of ~400 engineers. There is always someone trying to do things the quick and dirty way and move on without consideration for how the other 399 people may be impacted.
Practicality beats purity, and all of that. Especially when it saves quite of complexity in the code itself – new contributors are going to struggle with that, too.
In short, the setup doesn't need to be manual.