Another guy I like to follow, Lord Karnage, has similar number of subscribers, but most of his videos get far fewer views, 6k-10k and he's got over 4,000 videos up. I've heard an interview with him about his business and tbh, it doesn't sound great. He'd make more money panhandling playing video games on a street corner.
On the other hand, Simon and Martina, 1.2 million subs, between 300k-400k views per video and 4 videos a month, seem to be living a decent middle class life in Seoul and then Tokyo. No idea how much money they make, but they've had employees in the past to help them with their video production. Some calculators seem to claim they're probably making something a bit north of $100k.
One of the things that I find really disturbing is that, every so often, google will just "change" the payment computation and suddenly people who were putting 50-60 hour weeks into youtubing to make a fairly minimal living are suddenly seeing their income cut by huge percentages. Eventually everybody will figure out what changed and things will settle down, but there's a few weeks seemingly every year, where my subscription feed will be full of people complaining or shutting down channels.