You keep stating this as if it is a given and well accepted fact. It isn't. It may turn out to be true or he may have just pulled a Flacco, but there are several arguments on both side of the ledger on this.
I have no idea if Foles is actually good or not. I know he played phenomenally well against Minnesota in the NFCCG and against the Patriots in the Super Bowl. And I know that quite often teams with inferior quarterbacks beat teams with superior quarterbacks. It happens.
And for the record, here was Foles' three-game playoff run....
vs Atl: 23-30, 246 yds, 0 td, 0 int, 100.1 rating
vs Min: 26-33, 352 yds, 3 td, 0 int, 141.4 rating
vs NE: 28-43, 373 yds, 3 td, 1 int, 106.1 rating (plus a TD reception)
TOT: 77-106 (72.6%), 971 yds, 6 td, 1 int, 115.7 rating, his team scoring 94 points in three games
That's pretty kick-ass. It's kind of the anti-Peyton Manning. Foles might be a pretty iffy QB who ended up having a phenomenal playoff run. Peyton is an all-time great QB who had a pretty horrendous playoff run in 2015 yet also won a Super Bowl. Here were Peyton's numbers....
vs Pit: 21-37, 222 yds, 0 td, 0 int, 74.4 rating
vs NE: 17-32, 176 yds, 2 td, 0 int, 90.1 rating
vs Car: 13-23, 141 yds, 0 td, 1 int, 56.6 rating
TOT: 51-92 (55.4%), 539 yds, 2 td, 1 int, 75.4 rating
I don't know if seeing Peyton's numbers make me feel better or worse......