Then why do you refer them as "best practice", can we use "common practice" instead?
When everything is described by a superlative, really, it's just 'average'.
Sites like Trip Advisor or Amazon, or anything with a rating system. The "average" person nearly always puts 4 or 5 stars for average products or establishments.
When I worked at a large non-American internet company, I know there were some internal discussions on how to deal with different cultural interpretations of numerical ratings (still unresolved AFAIK).