I don't mean accuracy in "did the WR catch the ball" because that means next to nothing at the NFL level. The windows are SIGNIFICANTLY smaller, the timing is substantially tighter and the placement for a host of reasons has to be spot on a lot more of the time.
Look at RG3 as an example. He had a completion percentage of nearly 70%. And? The problem was that he didn't need to do the things that Pro QBs needed to do no matter how much his fans protested that he would learn. When he got to the Pros, his first season, he mostly ran his way to success with limited pass requirements. When he was forced to play as strictly a pocket QB, he suffered mightily (unlike Donovan McNabb later in his career who had perhaps the best game of his career on a badly sprained ankle that barely allowed him to walk to the LOS)
I'm not saying that Goff can't.
I'm saying that it concerns me.
Remember, almost EVERY throw in the NFL is contested, with someone closing on the pass. Almost every one. How often do we see passes in college with no one within 5 yards of the WR? Now think... If the ball were a little behind the receiver in the pros, is that still a completion? Probably not. Might even be an INT.
Jameis Winston found out that difference all to quickly the first five games of the season and there were plenty who said he was the most pro ready QB to come out since Luck. Dude got ravaged as a rookie QB those first five games and it took serious adjustments and the re-emergence of Doug Martin to allow him to catch up to the speed of the game and understand how different the Pro game is. His "accuracy" in college wasn't a question of the "completion" stat in college.
So, yeah, I have concerns about Goff. He's not off my list, but I have concerns. I have concerns about all of them, frankly.