I agree with you that he's clearly better than QBs like Taylor, Bortles, Mariota, etc. And by the way I don't think Garropolo qualifies since he only had 4 "real" starts. His 5th was a preseason game (and he threw two INTs in it anyway). No one can tell me JG is a top-10 NFL QB right now...

Ranking QB play the way sites like PFF do will always still be somewhat subjective. None of these are gospel. But if you look around at others you can get a general sense of what a QB really is. FootballOutsiders rated him 6th overall in 2017: [www.footballoutsiders.com]
ESPN's QBR system rates him 16th: [www.espn.com]. Average these three out and he's about....13th.. That sounds about right to me.

Purely statistically Goff was top-10 across the board: QB Rating (5th), yards/attempt (3rd), yards/completion (1st), TD% (4th), INT% (7th), completion% (17th), yards/game (10th).

But is Goff a solidly top 10 NFL QB right now? Probably not...yet. But the way he has ascended under McVay and LaFleuer (and Olson) was so impressive and he's clearly not a finished product. You watch guys like Brady and Rodgers who are SO established in and masters of their systems go to their 2nd and then 3rd reads in nanoseconds. Goff does not do that yet. He holds the ball too long on occasion because he is still relatively new to the offense. But he already is better at going to his 2nd read than Bradford ever was. And to me he also learned to throw the ball away better as the season progressed.

Goff goes into 2018 able to focus on the nuances of his mechanics and his offense- not learning the basics of them. That's a big difference for him. Under McVay Kirk Cousins improved his QB rating by 15 points in his 2nd season as a starter. Now I highly doubt Goff is going to go from 100.5 to 115.5 next year. But clearly he's on the right path and assuming they keep the talent around him and keep protecting him well I love where he's heading.