Your first sentence would only be true to the casual fan that does not understand football. Many of us can look at a Dline that is drawing double teams thus leaving clean shots for the LBs to get to the QB and know that it is the DL that set it up. So those people would not panic about the DL only getting 7-8 sacks a year while the LBS are topping 30+ .
The second paragraph is absolutely false. Again the DL may not get a lot of Sacks. However, they are still responsible for pushing the pocket. When you hear about an OL maintaining a "Clean Pocket". That means that the DL is not doing their job. When you hear the announcers talking about the QB can not get his feet set because he does not have a clean pocket. They are getting the job done. Even if the DL is not getting any actual sacks. Moving the QB off his mark and outside the pocket is what leads to most sacks.
@ShortSideOption @Middle-aged_Ball_Coach I know I have oversimplified this but would you agree with my assessment? You have both done a great job explaining these types of things.