Since 2021 SoundCloud has paid independent artists through fan-powered royalties. Each listener's subscription fee or ad revenue is split only among the artists they actually played that month. The more of someone's listening time you take up, the bigger your share of what they paid.
Streams only pay once your track is monetized. Independent artists turn that on through SoundCloud for Artists, which takes an Artist or Artist Pro subscription and an account in a country where monetization is available. Artists who release through a distributor or label get paid by them, on their terms, and the per-stream rate on those statements can differ from what this calculator shows.
Free, unmonetized plays still show up as streams on your stats page, they just don't earn anything. If your numbers look high and your payout looks low, that's usually why.