Someone says "it's best practice" and the room moves on. That is largely what the phrase is for.
The practices themselves are usually sound. They came from somewhere real: an estate of a certain size, with a team of a certain size, a risk appetite, a budget, a maintenance window somebody could actually use. Someone solved a problem well enough to write it up. Fair enough.
What travels is the recommendation. What stays behind is every condition that made it work.
So a design built for a team of thirty gets recommended to a department with two. A patching cadence that assumes you can take things offline at will lands somewhere that can't take anything offline before December. The advice was right where it came from. Here it just costs money and gets quietly abandoned in month four.
The question worth asking is a dull one, and it works. Best practice for whom? Written by whom, running what? If it came from someone who sells the thing being recommended, it's a sales document with good posture. If it came from a standard, it's a floor, and a floor is there to be met rather than admired.
None of which makes the practice wrong. It makes it evidence. You still have to do the reading, and the reading is the bit the phrase is used to skip.
Best practice tells you what worked somewhere. It doesn't tell you where you are.