Funny that in is this website, numbers prediction are always too high for Xbox but too low for PlayStation... biased much ?
Not bias... it's expectations. The community here generally expected this generation to be much closer than the previous one, this extends to the tracking team. Xbox quarterly reports being more vague than before (due to the big price gap between Series S and X) is also making revenues less meaningful/reliable for extrapolation. Xbox sales are extremely difficult to accurately estimate, this is why I never take any estimates very seriously, can't even trust Famitsu's numbers for the matter. But I respect most relevant estimates because they represent a knowledgeable person's hard work, which does apply to VGChartz.
That said, the leak's November figures were a disaster for Xbox. They lend weight to a lot of arguments that I and some others made, but even I didn't think it was going to be this bad. Series S is looking more and more like a misfired product, Series X too might be misfired in the sense that it's very expensive/difficult to produce in true mass quantities. Series S was likely carried by the pandemic and the limited PS5 (and Series X) availability relative to demand.
Let's see what Starfield can do because Xbox is in serious need for a killer app right now. Then again, Xbox's biggest problem may be its redundancy to the millions of players who are switching to PC.