He doesn't have the money to buy it. At very best, he is worth $200 million. Chelsea's asking price being $2.5-$3 billion makes it impossible for him to own it completely. He could try to buy it in partnership for a little stake in the club. But even that will not be a good decision because the previous owner, who is a billionaire, was putting his own money into the club because Chelsea has not been a profitable club lately.