Not really an anomaly; if you manage to make something the kids on Steam are looking for and simple enough to run on potatoes, then you hit it big; doesn’t matter who you are…
However those kids are salty beyond mount everest’s heights, so good luck with that 
Btw, UE4 runs on outdated hardware. You just need to understand its scalability methods.
And the 5% roys… Well, if you have steady income every month then good for you; but most indies make money only around two weeks after their game release (when it’s not a total flop) so paying 2 years of forced subscriptions to cash in two weeks of random revenue just isn’t suitable to the majority of indie game makers out there. I believe Epic is very well aware of that and were smart enough to adapt their licensing model to such reality.