You do know the guy he is today isn't the guy he was four years ago, right? Why do we care about his career ERA?
He's got a top-15 xFIP pitching in front of a bad team and a very low LOB% that won't keep. He's whiffing guys far more right now than ever before. He's about as good as he was this year as last, except he's back in the rotation. The way he's pitching right now, he's pitching like a guy you put near the top of a rotation and don' think twice about it.
The reason he's available is because he hasn't always done that. But if he had, he wouldn't be available. So you have to take the good with the bad here.