Combat experience.
Take U.S Navy seals--why are they so respected by everybody? Combat experience. They have had so many failures, they have had so many successes---but all of this adds to their combat experience across globe in different environments--something unmatched by majority of other SFs in the world.
Now, just google SSGs and Paratroopers..and see the difference in combat experience.
SSGs have operated in foreign wars (Soviet-Afghan war), have conducted operations in Middle-East, have been part of a decade long war on terrorism in some of the toughest terrains in the world, and have successfully conducted operations whether dealing with plane hijackers or clearing out terrorists from extremely complicated set ups in real life.
Paratroopers don't have that real life combat experience in so many different situations etc.
SSGs training regime is tougher than Paratroopers as well. For example, while paratroopers did 100km march in the video, SSGs are required to go 120km to 150km with heavier loads and harsher conditions (no paved roads here).
Idiots like
@sms will bring up one or two operations from 40 years back to put down SSG...but they don't realize that the very fact SSGs have been involved across spectrum of operations is what makes them superior to other, less experienced, forces. Do you know how many bouched operations one can pull out for Navy seals or British SAS? lol...