Going along with Ok4450s comments - if you look at the part numbers at NAPA for a “NAPA” part and at Autozone/PepBoys/Advance Auto/etc, you’ll often find that the part numbers are almost perfect matches for the store brand versions of a given part - showing that they’re from the same supplier.
For example - a balljoint for a 1998 Camry:
NAPA: Master Ride Chassis 104218
Autozone: Duralast 104218
Advance Auto : TRW 104218
So you can see that they’re all actually buying them from the same source, though Autozone and NAPA are relabeling them as store brand parts. They could all be made by TRW, or TRW might have bought them from a supplier - but there’s no reason to believe that the quality is any different on those parts.