I'll agree that the factory loads can be as good a quality as some hand loaders produce. I'll even agree that some factory loads are better than what some hand loaders produce.
But the factories aren't gong to produce loads tailored to my needs, or what works best in my rifles. They are going to produce loads that will work fairly well in most rifles, and fit every production rifle.
Take a look around this site, or any shooting related site of your choice, and you will see many phrases such as "each rifle is it's own individual", or these loads work well in my rifle immv ( individual mileage may vary) Take a look at any of DC's posts when he mentions a load. He will tell you right there that these are accurate and safe loads in his rifles, use at your own risk.
That is because only handloaders can tailor make a load to perfectly fit an individual rifle, and make it shoot it's best. Factories want you to believe that 1 MOA is great, and you shouldn't expect to do better. If you happen to shoot half MOA, you have an exceptional rifle and must be a great shot.
I happen to view half MOA as a minimum line of acceptability.