There are 1.4 billion people in China. You’re showing me a couple of people doing who knows what in a clip of unknowable provenance. This is not the hill to die on, my man

Restaurants in china are legally required to use oil traps like that and the oil must be removed. It is usually reprocessed to be used for industrial purposes. The fact that those people were possibly possibly illegally collecting it to sell to a company that reprocesses it does not at all mean that it's going to be used as "gutter oil" in restaurants any more than someone collecting empty cans from a trashcan means they're going to reuse those cans in a restaurant.

Gutter oil used to be a major issue in China but the Chinese government cracked down on it a lot a few years ago.

I recommend watching this video about it: https://www.youtube.com/watch?v=G43wJ7YyWzM