Can't speak for all of them, however, Signal uses websockets as far as I know to pull new messages. This way you still get push notifications, but it comes with drawbacks, because (1) it needs it's own background service, yes, and (2) messages could still be delayed. However, I can live with that knowing the caveats.
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Can't speak for all of them, however, Signal uses websockets as far as I know to pull new messages. This way you still get push notifications, but it comes with drawbacks, because (1) it needs it's own background service, yes, and (2) messages could still be delayed. However, I can live with that knowing the caveats.