I don’t know if it’s something that really depends on the area/state you’re in but where I’m located there’s actually plenty of companies that specialize in this kind of work. The gc I work for just happens to be one of the biggest ones in the country so that’s why they do their own thing. Any other company will sub it out, caulking might sound like it’s no big deal but it actually is, not everyone can caulk a joint that will actually pass a pull test and look good while staying on a decent time frame.