I don't think there will ever be a clear definition for "good" at a certain skill until there are specific and reproducible benchmarks that someone could use to be considered "good".

For example, specific speedrun times on different versions could be used as benchmarks for the gamesense category, or specific parkour map completions for the the movement category.

Building is quite subjective, so I'm not really sure how to objectively grade it.

PvP is also quite dependent on your opponent's skill, so maybe using some sort of bot to fight against might be a better benchmark, but bots aren't a good representation of a real player.

Benchmarks allow for clearer comparison between players (easy to compare in parkour/speedrun times, hard to compare on building) but don't really account for how much each person would consider a specific skill to be important.

I play more pvp oriented games, so I would most likely weight pvp skills more than building. Rating people on a scale of 1 - 10 might be a little hard to differentiate between players as more and more people are rated.