About restaurants, there are big problems even besides kashrus.
It could be Pikuach Nefesh becauise many of these workers come from outside the country and bring in all kinds of diseases like T.B. and Hep A, and B, and C, and Leprosy (not Tzaras like mentioned in Torah, but a far more insidious version that may not be curable and causes limbs to wither away and literally fall off).
All these diseases are on the rise because of who works in restaurants and what they bring in with them.