GP usually takes a week or 2 (maybe 3) to put up their ratings.
Most sites will just use spreadsheets and order things according to raw neutral dps - which is OK for a very basic listing, where the priority is being 'first' to produce a list.
GP however takes into account, the meta, the mons uses/relevance, as well as moveset dps. They use full simulations against multiple meta relevant opponents with all movesets.
This takes time.
Sure, in many cases the listings they end up with will be similar to pure dps spreadsheet lists, but it is the differences that are key to making GP listings the most reliable and most robust around.
I personally am happy to wait while they do all this work for us, to give us the most robust and meta relevant rankings.
