Superworms are a little debatable, but not because of the issues that mealworms have. You want to steer clear of mealworms because they have a high chitin-to-meat ratio (chitin being what their shell is made of) meaning they are difficult to digest. Superworms have a lower chitin-to-meat ratio, making them easier to digest (however, note that your bearded dragon typically needs to be at least 16 inches in length to properly digest worms--the short explanation for this is because at this length, the bearded dragon's gut straightens out).
What some may argue does not make superworms suitable staples is that they are somewhat fatty and some believe they are not quite as nutritious as the other staples. However, from nutritional analysis, they're relatively similar to crickets. They're also one of the few staples that you have to monitor how much you feed, as they can cause stomach problems if eaten too quickly or too many at one sitting, especially if you are first starting your bearded dragons on them. However, at worst, your bearded dragon will just regurgitate the excess.
If anything, supers can be used as staples as long as you know what you are doing, properly feed them to your appropriately sized bearded dragon, and ensure your temperature and habitat settings are up to par (for proper digestion). They're relatively similar to crickets nutrition-wise, so supplementation and variety never hurt.
Not sure about microworms, but if you are referring to micro-superworms, micro-superworms are basically younger and smaller forms of superworms, generally before their shells fully develop, making them much softer (and even possible for younger bearded dragons to eat).
Note that I am not particularly advocating for superworms, especially when there are, what I consider, better worm staples. Just listing all of the worm staples I am aware of.