The basic "error" for these data mine company is not how they estimate, it's that their source data is already not accurate. Ie, when they determine revenue, they are using how many new games claimed during that period of time from source like steamdb/steamspy, probably have per region information. But steam are not the only platform that are selling steam keys, and use Steam figures "only" is significant but not accurate as there are still other platforms on PC that still takes significant chunk of the market. (ie. EGS, GOG, HumbleBundle, itch.io, key reseller: GMG, CDKEY, etc.) If your game published and selling on many platform, chance are about 5~15% could come from those secondary platforms depending on how they run seasonal sales. Thus, the key redeemed on steam does not mean it's always the steam price at the time.

That and revenue not including mtx or IAP is ridiculous in claiming recent gaming trend or consumer behavior. If you have access to some internal financial reports from company that publish wide variety of games, say EA or Sony's game division then you get a bigger picture and it's easier to extrapolate from those data. For example, The Final is smashing the F2P shooter currently and not even showing up in this report for the hit game in 2024, it's revenue is pretty much guaranteed to be top ranker for 2024.