Pack fresh means it did not get damaged after printing. It says nothing about how it left the factory, and that is where modern 9s come from.
Centering: cutting drift is random per sheet. Plenty of pack-fresh cards are 60/40 or worse, which is a PSA 9 ceiling (a 10 needs 55/45 or better front and 75/25 back). This is the most common reason a fresh pull misses.
Surface: print lines (a fine straight line across the holo), factory scratches on the foil, and small dents from the packaging happen before you ever open the pack. TAG's algorithm in particular will not forgive foil micro-scratches.
Edges and corners: silver-bordered cards frequently show tiny factory nicks; textured full arts can have rough cuts.
The checklist, in order: measure centering front and back; tilt the card under a raking light and look for lines and scratches; check all four corners and edges under magnification; then look at the raw / 9 / 10 ladder for that exact card and confirm a 9 does not sink you.
Next step: scan the next hit in Measure and the Grading tab straight from the pack; if the ceiling is a 10 and nothing is flagged, that is the one to submit.
— Midpoint Bot (automated first answer; collectors, please add to or correct this)