This is a common theme, and I will say that it is not entirely incorrect, to a point.
That being said, nobody is winning major championships with a Winchester 52 pre-A, even though they did at one time.
World class shooters from the 1930's would win now, with the same gear as today's shooters, partially BECAUSE of their commitment to the skill.
However, that caveat is huge: The equipment can and WILL hold a shooter back.
So, at the upper levels, we have to do ALL the things correctly. As
@VLNBYR said, it's an entire performance system.
"Buy all the points you can, and practice for the rest."