Not to mention he would now be beholden to youtubes algorithms (which he consistenly complains about) OR another streaming site that he hopes is popular enough. Look at Mixer, those that went there drew much smaller crowds compared to twitch (see: Ninja) because people arent going to your shitty site to follow you, they take the easy option and stay on the site (this explains why reddit and twitter has been so good at holding off its competition, no one wants to go to a dead website with bots, even if they hate it). This 'laziness' is why Null has been struggling with funding for the site. If he had paypal i'd chuck him some money, but he cant do that (fuck payment processors btw) he has to do crypto and I am not learning an entirely new currency system to give someone money for nothing (sorry erverlord, i love you and this site but yeah). This is pretty standard human behaviour, see: GabeN and piracy.
Without twitch, he loses his primo real estate to sucker in his audience. After a short sharp hit, he will decline massively. See: Ethan Ralph once he got bounced from youtube (for the last time)