Well, if you want to get into it, here is my big problem whenever you talk about the relationship between hardware and software sales. As far as I can tell, you seem to believe in "magic". I know you don't use the word "magic", but whenever you describe how sales work, it sounds a whole lot like magic to me. This is because what you mostly do is describe what doesn't cause sales. You don't give an alternative explanation of what really does cause sales.
Most of us assume that software sells hardware. So when you come along and say that even the best game, like Animal Crossing, won't increase monthly sales for more than a month or two, then you need an alternative explanation, and it needs to be a good one.
As far as I can tell, you don't have answers to questions like these where most of us assume that it is the software selling the hardware. So, I just assume you believe in magic. All of these sales are happening by magic. I know you believe that a big software title causes a spike that lasts a month or two, and I know you believe that a new hardware model can increase sales for a while. Other than that, it appears that you believe in magic. Because you do a whole lot of denying that software is selling hardware, but you usually don't provide a compelling alternative reason.
I deny nothing, unlike some people here. I mean, do you actually read my posts, or do you just skim through them? Because it seems that you're more intent on mocking me than in accurately representing what I say, and basing your "rebuttals" on that.
Overall libraries are important. Strong support over the system's life is important, as rapid loss of support close to the system's replacement coming out is associated with more rapid later-life declines. In other words, a strong selection of games released across a system's primary life cycle at minimum is a major factor that increases the perceived value of a system.
But we're talking individual games here. Individual. Games. And while a single game can and often does move hardware, not all software causes appreciable hardware sales growth. Sure, a popular game might sell millions of copies lifetime, but how many of those millions actually bought the system for that game? How many wouldn't have bought the system had that game not existed?
Tell me, where do you see substantial hardware growth from Super Mario Party in this graph?
Again, we saw an increase of only 6.5%, or 2805 units, from the previous week, indistinguishable from the normal week-to-week fluctuations. There were similar or larger jumps than that in weeks where there were no major software releases. But for the sake of argument, if you assume that 100% of the sales increase in Week 40 was due to Mario Party, then at most only 1.96% of new Switch owners that week bought a Switch just for Mario Party (MC & Famitsu both never include digital). More realistically, hardly anybody who bought a Switch that week decided to do so because Mario Party dropped. Nearly everybody who bought a copy were existing owners. And SMP's sales plummeted from its launch week numbers, so unless you want to argue that it somehow sold more hardware relative to its weekly sales as it went by, SMP did not cause any sort of increase in hardware sales in the long term, either, not just initially. Hardly anyone considered it the game to get them to plunk down ¥30k on a Switch.
Again, there's a difference between buying a system for a game and buying a system with a game. And then there's the game that just shows up and most people don't bother with at first, but it still is recognizable enough and catches enough people over time to maintain steady long-term sales as people buy it just to have something fun to play. That's Mario Party.
Now here's what a real system-seller looks like:
Monster Hunter Rise, the most recent major system-seller on the Switch, was part of a series that consistently causes pronounced growth the week of whenever a new entry releases (barring a few counter-examples). It sold 1.3M copies at retail in Japan (possibly upwards of 2M or more if we include digital) and caused Switch sales to triple from what they were the week before. In absolute terms, the Switch sold over 178k more units than it did the previous week. Now, MH games are the kind of games that burn very bright but sputter out quickly, the exact opposite of a game like Mario Party. It dropped to 277k copies in its second week and was under 100k/week by its fifth week (with a one-time bump to over 100k during Golden Week). After just one month, it was selling at a low enough level where nobody could seriously argue that it was a continuing driver of Switch sales. Three months after its release it had dropped to under 10k copies per week. While it did have a residual effect in its second week, perhaps aided by the limited edition console released alongside the game, by Rise's third week the Switch was back down to around where it was the week before Rise released, and, aside from the Golden Week bump, the Switch has been on a downward trajectory since, even before the OLED was announced. MH Rise was a system-seller, but also a clear demonstration that the ability of a game to sell systems is not a long-term factor.
If I had time, I could drop many more examples (this post has already taken me over an hour to compose if you include creating charts), but you get the point. While there are a fair number of games that cause obvious (and always relatively short-term) growth in hardware sale, the vast majority of games have minimal to no ability to, by themselves, cause sales growth, and for most of them it's unlikely that their absence alone would have resulted in measurably worse sales for the system.
As for why some systems peak earlier or later than others, that has to do with a lot of other factors besides the games on the slate. The 360 & PS3 peaked after their slimline models were released. Those models caused immediate and pronounced spikes in hardware sales (the 360S more so in the U.S. than elsewhere) and a sustained increase in baseline sales (the PS3 Slim was also concurrent with a price cut from $400 to $300). Neither system had lineups that year that were mind-blowing relative to previous years. The PS2 is another example of a non-software factor leading to sustained growth, in its case its first price cut in May 2002. Speaking of price, the PS3 & 360 both took longer than earlier systems to get down to the prices they were at when they peaked, and at any given point in their lives were more expensive than the PS2. Nobody can look at any specific game on the PS2, even any assortment of games released in a relatively narrow time frame (say, a few months) and say "That's the cause." No, the PS2's sales grew because a lot of people that were holding back decided to take the plunge once Sony slashed its price by a third.
Individual games can and often do drive sales growth... in the short term. Most do not, however.
Price cuts frequently drive sales growth, and is one of two factors proven to produce such growth in the long term (i.e., many months).
Hardware revisions frequently drive sales growth, and is the other factor proven to be a long-term driver.
Limited edition systems often cause short-term sales growth, and have probably assisted most games they're associated with (when they are released alongside a game).
The overall long-term health of a system is determined by the interplay of overall games library, initial pricing, marketing, regional differences in spending habits, the occasional external factor, and a host of other factors that influence how potential customers perceive it as a value proposition.
Saying that Super Mario Party doesn't cause any obvious sales growth does not negate any of that.
And with that, I'm done with this conversation. I've said all I need to say and all I care to say, and I have other stuff to do.