FWIW, NDS 08 is a 53 week year on VGChartz (just like 2020). Through 52 weeks, NDS 07 was indeed slightly ahead.
That said, per Nintendo's FY shipments, NDS FY07 (04 07 - 03 08) was ~30M and NDS FY08 (04 08 - 03 09) was ~31M, so they are definitely neck-and-neck.
I think NSW 21 will take the #1 spot in the end. Much stronger predicted SW lineup than last year and they had supply issues all year last year that they've now had time to prepare for (we're still seeing shortages, but not as bad). If they can get the Pro revision out in Sep, I expect 33-35M. If its a Nov release, maybe 30-32M. If it gets pushed to next year then be right around 2020's range.
I'm really not sure how this year will turn out yet, other than I think Switch will have another really good year. But I don't know if it will be up or down from 2020 yet. It just seems incredible to me that a system could set the all time annual sales record in its 5th year. At a certain point sales come down for every system, no matter how successful it is.
On the other hand, you make a lot of really good points. All signs indicate that software releases will be stronger this year. A new Switch model will definitely boost sales. And most importantly, Nintendo should be much more prepared this year for Switch's high demand. If Switch '21 outperforms last year, then it might be the last point that is the most important. Who knows how much the Switch could have theoretically sold in '20 if Nintendo had ample supply? That is how I make sense of it anyway. I can see '21 being up YoY, in the Switch's 5th year, just because of supply shortages in '20.
I think anyone that's expecting NSW 2021 to be down is making an implicit assumption that I disagree with and that the numbers are starting to challenge. That assumption is that demand was satisfied in 2020 at 28M and so we'll see it taper off, leading to a drop (small or big).
I don't think the bolded is true. I think 28M is a result of a supply & production bottleneck. There's been a lot of discussion on VGC about the "why" of 2020's impressive performance (Covid + ACNH), but I think more focus should be directed on "how" and "what".
What: NSW matched or just fell short of peak NDS years with ~28M sales in 2020. Global gross consumer spending for this device was ~$7.7B, vs NDS peak of ~$3.8B.
How: Nintendo suffered major production issues in Q1 2020. Slow adaptation of increased production leading to further supply issues in Q2-Q4. Relatively moderate software lineup. MSRP/ASP more than 2x NDS MSRP/ASP.
We don't actually know what true demand was last year; 28M sales is a result of supply constraints and true demand may have been 30/35/40M.
I see several scenarios possible here (ignore the specific numbers and just consider the general premise):
A.) 2020 demand was around 30M. Demand declines in 2021, resulting in sales of 20-25M
B.) 2020 demand was around 40M. Demand declines in 2021, resulting in sales of 30-35M
C.) Demand persists at 2020 levels, and sales = whatever Nintendo supplies
This is without considering the boosts/advantages of new software & hardware 2021 can bring. Not even going to touch the point of price-drops, because I think Nintendo will find that idea untenable when demand continues to outstrip supply (maybe they consider this if they believe Scenario A to be plausible).
Right now, the impression I have is that we are clearly somewhere between B and C. If we start seeing reports/evidence of continued supply issues, then we can start leaning towards C.