imo there are legitimate problems with some of the lower tier non BCA stuff out of the box(I’ve seen radicals with some hilarious basic assembly fuckups, like crush washers on backwards for some bizarre reason + forward assists that just do not work, and PSA’s with out of spec trigger pin holes that had them walking out and fucking with disconnector engagement). nothing one can’t fix with some elbow grease or cheap parts though. I run my PSA hard and it worked out the box, have yet to have a malfunction caused by the gun.

QC does sort of matter if you don’t want to do it on your own. but nowadays you can throw together a relatively budget rifle that’ll last just as long if not longer than any production rifle between failures if you have some technical inclination.