Your question was "What would be the benefit of using [TH stompboxes] before and amp over those in the DAW."  I answered that question.  Concepts like "improving the tone" and "better" are subjective.  None of these emulations of either stompboxes or high-end studio gear would exist if we wanted some objective concept of "best".  Pick the one that you prefer the sound of.  There is no "better" otherwise.  An LA-2A before TH2 isn't going to sound anything like the RSS compressor in TH2 but neither are "better" (and like I've said, the RSS is going to be more of a "classic" effect for guitar -- whether you want that or not is up to).