The "fact" that he is not ready is evidenced by the fact that he is not playing.
None of us knows how he is or is not progressing. Anyone who watched him in any of preseason games (think the Minnesota game, last preseason game of the year) and thought he was dialed in is nuts. The first drive vs a base Vikings D looked great....scripted plays I am sure. Then after that, keystone cop.
I am not doubting Goff will get there but, sadly, the only source there is to go by are the coaches that see him everyday. Until then the last time we saw Goff play he was in over his head.