Well, I'll say this. Are some of his pure stats "padded" from garbage time games/losses? Of course.
But as for the ESPN QBR the article points out (which adjusts for strength of defenses, situations, other context, etc.)? The last 5 years he's been rated 8th, 8th, 23rd, 6th and 15th. (Avg ranking: 12th)
Similarly, with Football Outsiders his past 5 years he has been 9th, 10th, 20th, 9th and 14th. (Avg: 12.4)
And PFF- 8th in 2016, 12th in 2017, 16th in 2018, 8th in 2019, and 14th in 2020. (Avg: 11.6)
Did the Rams acquire a top 5-6 QB? Absolutely not. Did they acquire a top-12 QB? Yes, they did.