Remember that every artist will have negotiated contracts differently with their labels and publishers so it’s never just going to be a case of money from streaming/licensing/downloads going straight to them. The reason Geoff Barrow makes fuck all from streaming is that he probably signed a bunch of crap contracts back in the day and then has to split it three ways + give up cash to whoever he sampled.
I’m guessing something like Intro by the XX, Teardrop by Massive Attack, Are You Gonna Be My Girl? by Jet, etc all make their writers more than enough to live on. They’re songs that regularly get placed on adverts, TV, and are still in the public conciousness.