Can this module read JSON or XML files?

Check out source Twig function.

Although I don't know how to use source Twig function to load JSON files, because I tried, No effect seen.
I still hope that this module can add this feature, such as through drupal_loads_json() or other names.

Thanks

drupal_loads_json()

That would just duplicate source function from Twig core.

/sites/default/files/json/test.json
Json Data:
{
"nid": 1,
"title": "Sample One",
"description": "Lorem ipsum dolor sit amet, consectetur adipiscing."
}

Use by Twig:
{% set data = source('/sites/default/files/json/test.json', ignore_missing = true) %}

{% for key, value in data %}
{{ key }}: {{ value }}
{% endfor %}

No output, Is there anything wrong with it?

source() just loads file content. It does not decode it. You need something like json_decode.

See related issue for explanations.

For such case I would recommend loading data in preprocess hook. That should be trivial.

function example_preprocess(array $variables): void {
  $json = \file_get_contents('public://test.json');
  $variables['test'] = \json_decode($json);
}