To me, it seems fiver is a legal liability.

You cant rely blindly on the services. In some countries, you cant do work-for-hire if you are a PRO member, so you have to know where they are located, how the laws are, and what their PRO allows. Musicians are notorious for not being business savvy, so they most likely won’t know themselves. Fiver probably waiver all responsibility in their terms, so you are on your own.

Further more lawsuits has become a “market” because cases are just decided in the courts by average listeners who are not educated in musicology or musicians, so the risk of getting tracks in return that can be cosidered ripoff’s are huge, especially when having generic work done like on fiver.

So, I would never consider using fiver for music that is going to be comercially published or released. I dont have the nerve.