“but I never saw a place advertise cholov yisroel and pas yiroel and be open on Shabbos”
You listed 3 things all of which are not necessary in order for the food to be “Kosher”. They are all chumros. People need to know how to differentiate between halacha and minhag. If you are machmir not to eat at places that are open on Shabbos then it is up to you to determine whether a particular establishment abides by your standards. Don’t just assume that because they are cholov yisroel that they are also closed on Shabbos.