How can I utilize the 5 positions of the minor pentatonic scale when it comes to Writing Riffs/Solos? HELP PLZ?

Ive Learned all five positions of the minor pentatonic scale, But I have no Idea in How to use them in my riff making. IMO the scales are useless, unless someone gives me an idea or shows how to use them. I hit a wall And I cant make a single riff at ALL! Ive been looking everywhere and I Can Not Find Any Advice on the topic. I heard If you learn guitar scales its easier. So I learned the minor pentatonic scale. But as you can see I don't know how to use them. It is very Frustrating. Do I need to them? Do i Need To Know any other scales? Do all good guitarists Know them? So If Any one Can Help I am pretty much begging for advice. PLEASE HELP!