The surfbar
Leave a tab open and let it run. The only thing here that earns while you are not looking at it.
A surfbar rotates advertiser sites through a single tab on a timer. You start it, you leave it, and it keeps going. There is nothing to click and nothing to submit.
It pays the least per minute of anything on the site by a wide margin, and it is the only one that does not need you. That is the entire pitch: it is not competing with the surveys for your attention, it is competing with an idle tab.
Coins land shortly after a surf session ends rather than while it runs, because the provider reports a session once it is finished. A single session is worth a fraction of a Coin, so the balance builds up rather than arriving one session at a time, and the counter on the page shows how far along the next whole Coin is.