Supermega was something they both started up mid-college education for both of them, they dropped out precisely to pursue the 'career' of Let's Player (and I guess just general e-celeb). So I think you really nailed it on the head here, they're going to follow that money.. though they sure started their fanbase by being pretty raunchy.
So essentially they're the rainbow icon during June of LPers, fake as hell and these days so laughably unrelatable its funnier than any of their content.
They were part of Cyndago, that had Ryan, Matt, and Daniel Kyre as a trio that would do comedy sketches along with Markiplier (before his big boom).
They pretty much stopped doing Cyndago when Daniel was shown to have mental health issues (depression I'm pretty sure), and after being hospitalized due to attempted suicide, he later had developed some form of brain damage that was past help and had his life support pulled.
Everyone pretty much stopped doing anything involving Cyndago, Matt,Ryan, and Mark banded together for a time to release content, but later grew apart which is where Markiplier's and Supermega's story pretty much starts.
Right now Supermega is in some weird boat where they are working off their audience since that is all they have. I think they can be funny even now, but it's a wary sense when watching a video. I think their Nascar stunt was great and it's cool seeing them be involved with something using their influence even Arin wouldn't do.
Recently on the topic of Super Mega and Oneyplays Matt actually brought up Oneyplays in one of the SA2 videos.
at 0:24
I've been skipping their stuff lately and have no idea if it's anything more then just noting it, but it's still nice to see Matt actually calling back to that when before he tried to distance himself as far away from it as he could.