Good view but it still doesn't explain everything.
Holiday months affect NA more than any other territory. When the PS4 outsells Xbox One over two to one during nonholiday months it is mainly because of countries outside NA.
According to VGChartz, NA accounts for less than half of PS4 sales. I don't see NA holiday sales making up for the gap the PS4 gains from outselling Xbox One over two to one outside NA all year.
According to the OP the sales gap during nonholiday months is substantial and this isn't new. It doesn't explain why VGChartz always has Xbox sitting at just above half of the PS4 lifetime total even during nonholiday months when the PS4 is outselling Xbox One over two to one. Lifetime totals never seem to reflect it. Their Xbox lifetime sales seem to shoot up out of thin air on occasion even during nonholiday months.
Add this inconsistency to other facts. I understand VGChartz isn't 100% accurate and VGChartz has a record of undertracking PS4 lifetime sales whenever Sony releases sales numbers. Microsoft hides all Xbox One numbers and Sony provides hardware numbers, so PS4 sales aren't as difficult to track as Xbox One sales.
If we go by all of these inconsistencies I don't think the Xbox One has sold 28.5 million. It seems like VGChartz may just be using PS4 sales as a reference to make the Xbox One lifetime sales just above half of whatever the PS4 lifetime is at any given time because it is an easy way to track Xbox One sales even if it isn't accurate. That would explain why the Xbox One lifetime total never seems to reflect the weekly and monthly reports where the PS4 outsells Xbox One over two to one.
