While I know PSA has had issues, I have never seen an issue with their stuff, and I have had a few and been around several dozen of them. When I shot 3-gun and helped run a shooting range, a lot of newbies showed up with them and never had any issues.
As of 2018, PSA owns DC Machine, who makes over 2K AR barrels per day. I have been told that during peak production, PSA can build 10K ARs per week. Even if they build to a 99.99% standard, a few lemons can make it out the door.
That said, I think the best hard use AR for the money is still BCM. Once in a while a quality issue will pop up on the web but they are quick to take care of it, and are few and far between.