Confused about purpose of the default property for inputs in manifest.yml

Is the “default” property of inputs supposed to be available in the operation of a plugin?
While developing a plugin… unless I explicitly define an “input” value in the netlify.toml, the “input” is undefined in plugin code execution. Even if the manifest.yml has a default.

So is the manifest.yml just for documentation?
If so, why do so many existing plugins list defaults for inputs, but never set a default in their plugin code?

Hey @moop-moop,
The manifest.yml is not just for documentation. I found Tara Manicsic’s tutorial on this really helpful:

And you probably already know about this repo but dropping it here for future readers of this post:

That said, it is surprising that you would get undefined if you set a default value in the manifest.yml. Can you share your repo or a deploy log?