not necessary disable dataProvider->sort

[nadirvishun]

why display dataProvider->sort?
if it disable we only can use:

$dataProvider = new ActiveDataProvider([
            'query' => BackendMenu::find()->orderBy(['sort' => SORT_ASC, 'id' => SORT_ASC]),
]);

but usually we use in this way：

$dataProvider = new ActiveDataProvider([
            'query' => BackendMenu::find(),
            'sort' => ['defaultOrder' => ['sort' => SORT_ASC, 'id' => SORT_ASC]]
]);

[dkhlystov]

If do not do this, tree may be broken. It is more actual for moving nodes. What you see is not what you get.
I think it's possible with some conditions for parent related tree. I need to inspect code before.
With nested sets it does not matter, because first sorting by 'feft' attribute, which different for all nodes and used also for sorting.