You mean he played worse when he lost a guy who was on track for 1200 yards and 12 TDs?
Shocking.
Counterpoint; he still had a bonafide #1 WR in Cooks to throw to, Robert Woods, who was also a 1000 yard WR. Good QBs don't need godlike WRs to throw to. Do they help? Absolutely, but not all need them. Guys like Rodgers and Manning made the careers of some WRs by making them look so, so much better than they actually were.
Goff rightly has issues people are pointing out, but at the same time i don't fault the Rams for paying out the ass to keep him. It's what the market dictates and they're primed to contend now. Better to pay the devil you know than go with some other unknown.