So far I myself still refer to the two sites when I want to check the transaction gas fees, both are still a little inaccurate, but that's all I can see, because I also haven't found any other sites about it that are more accurate.
True, based on my observation when you follow the ethgasstation and it will be saying if you need at least 331 gwei but the reality is different because there are some token transfers that got confirmed by the block is putting only 231 gwei as its fees. It's a very interesting thing to be discussed. The ethereum fees are so crazy these days.
You will never find a site with high accuracy. It's about how good you can get the actual data about the fees on the site like etherscan or bloxy