Yeah. In casual language sure, Phil's addicted to this shit, but in clinical terminology it's important to note the distinction between an addiction and a compulsion. The terminology can get a bit muddled because addictions can cause compulsive behavior, but all compulsions are not addictive behavior. In pure clinical terms Phil's relationship with this game is most likely not an addiction, he doesn't have a physical or psychological dependence on playing the game to the point he doesn't even feel the reward of getting sweaty half-naked.jpegs and winning matches of Bejeweled while they dance he just needs to do it to feel normal. He isn't sinking money into WWE Champions because he NEEDS a hit, he's doing it because he WANTS to and has poor impulse control.
What Phil has regarding this game is a compulsion similar to the general compulsive behavior he regularly exhibits. He talks about it in various different aspects of his life that there seems to be this voice in his head chanting "I have to. I have to! I HAVE TO! I HAVE TO!!" that crops up with various different activities. With WWE Champions it seems like he literally feels like he's 'Gotta catch 'em all'. When he gets a bronze PS trophy and says, "OHH! Just got a trophy! 'You just tied your shoes for the first time' Huh-huh, NICE!" and people wonder why he acts like this about a digital sticker you automatically are given during the tutorial. My guess would be a generalized Impulse Control Disorder. We've certainly seen him exhibiting compulsive shopping periodically, he seems to exhibit Intermittent Explosive Disorder daily on his streams, there's literally hunderds of examples on this forum documenting and commenting on instances he exhibits poor impulse control.
Here's a fun one. Phil says that when he was spending thousands on credit cards travelling all over the country to FGC tournaments, one of the things that got him in his original large amounts of credit cards debt, he thinks was addicted to it, but describes it as a compulsion: "THIS is my hobby, I HAVE TO DO IT." He wasn't constantly hunting down any back alley tournament because he NEEDED a hit, he was blowing tons of money because he WANTED to and couldn't stop himself. Timestamp @ 10m58s