There is and there isn't just a pool of money that goes to beyonce, the weeknd and taylor swift... i say there is because what actually happens is, the collecting societies will collect the money, then distribute it based on streams correctly to the artists/writers/producers etc that are registered. now if it so happens that a collecting society can't find the correct person to distribute to, the money might sit for a while before it is divvied up between the biggest players, so that would mean taylor swift, elton john etc might get a share of any unclaimed royalties.
When i worked in the business, we would often have many a drunken night talking about how we should just record the rain on the roof, upload it and use the "royalties" as beer money.
for the most part, being on spotify does pay, but i think people don't really understand how the pie is cut and when the artist actually gets a slice. there are many routes to being on spotify (or any streaming service), the router for taylor swift will be different to the route for your dad's garage band, as will the payout.