I may be biased (being Chinese) but I feel like the sauce packets are completely unnecessary these days. Maybe 30-40 years ago when takeout Chinese food was still something of a novelty for Americans, but I would think most American households have soy sauce, Sriracha, and mustard (well, maybe not spicy) these days. And if not, they have easy access to them from any big grocery store.
But I think, in the interest of reducing waste, we should expect people to pick up their own sauces to use rather than pre-supplying all of them under the expectation that they only might be used. Like, imagine if pizza places threw in 10 packets of ranch dressing with every box of pizza you ordered because some people like eating pizza with ranch.
You won't get any argument from me! Spicy mustard all the way. Or even mix it with some kewpie mayo and use it as a topping for noodles...orgasmic.
But I know the normal yellow bottle French's mustard is still a staple of the American household, so I am assuming most USians ordering Chinese takeout on a whim don't have that at their immediate disposal.
Those are even worse! They did that here and it's the stupidest "solution" I've ever seen. They took away the plastic bags and started charging everyone for paper bags that were always free before. Then they brought in bags that use 100x more plastic and continued charging people. The whole thing feels like a ploy by the grocers to add yet another upcharge to grocery shopping. Fuck!