One of the sample sets (Showdown Usage) uses Eviolite Scraggy, so it already can be seen that it is recognized by Smogon and is more than a very small niche. According to the analysis, Eviolite can be used on Scraggy if you want to be able to set up on more offensive foes like Pawniard and Onix. Offensively, it's probably outclassed by Pawniard, which doesn't need setup to be good and can do more than just attack, like setting up Stealth Rocks. If you want a dark type sweeper, Scraggy is the best option, if you want utility, Pawniard is the best option. Though really Scraggy is still hard to justify using when Pawniard has Swords Dance + Sucker Punch.
tldr Scraggy is viable but outclassed by Pawniard in most cases.
Hope this helped!