I think you should remove the term "pyramid scheme" from your post because it's very negative in the cryptocurrency world. In addition, matching this term with the name of the project, unfortunately, negatively affects its image.
Exactly what I was going to say.a referral program that works like a "pyramid scheme" but without a scheme 
If you say something is like a pyramid scheme, but isn't a pyramid scheme, then people won't see the word "isn't", they'll just see the phrase "pyramid scheme". It may help for illustration purposes, but I think it will be very counterproductive. If this isn't a pyramid scheme, then just don't mention the phrase at all.