Because all of the really big (3m+) selling games in Japan are on the Switch.  On top of that, most Japanese PS5 games are also on the Switch.  For the vast majority of Japan, they can just buy a Switch and be done.

Japanese third party support is going to keep PS5 from cratering in the land of the rising sun.
No matter what, it's still going to get Final Fantasy, Dragon Quest, Monster Hunter, and all of Square's/Capcom's AAA output by default.
That alone will put its sales above, say, the Vita.

I don't see any real chance of PS5 falling short of 5m in Japan, not when it's going to be getting basically all Japanese AAA games for the remainder of the generation and likely multiple years into the next.

It's sold almost 2 million in under 2 years while severely supply constrained, no way it doesn't blow passed 5m in the coming years as both supply and library improve.

I was just going by tracked sales, we'll likely never know how many are actually in the hands of Japanese gamers.

The PS4 got most of the big third party games and had a lot going for it. But it still failed to reach the 10mil mark.
Now many franchises that previously only released on PS in Japan and/or sold the most on PS are not only releasing on Switch day one but the Switch version almost always outsells the PS version.
Starting with the PS3 Playstation was in a decline with many franchises that pushed the PS1 and PS2 to it's hights also declining in Japan, like Final Fantasy and Gran Turismo. Since then other previously big franchises on Playstation have also declined like Resident Evil and Kingdom Hearts.

With the Switch dominating the small to mid sized third parties and having almost all multi million selling games in Japan for itself the PS5 was never going to sell as much as or more than the PS4.

The low software sales of the PS5 don't paint a positive picture for the future of Playstation in Japan.
Final Fantasy XVI next year will show us how much a game can actually sell on the system, but it will likely end up as the first FF in ages to sell below 1mil lifetime.
Most of the PS software sales are happening on the PS4 right now.

I expect the PS5 to still reach a decent number of sold consoles, like 6 or 7mil, but until WW production ramps up a lot possibly over half of them are being resold outside of Japan.
The big AAA third party games aren't enough to push a console to actually high numbers in Japan. By far the most games that sell over 100k are also on Switch or only on Switch.

Agree the PS5 will do 7 million, though I'm not even sure it will do 8 million. PS3 did 10m, PS4 did 9m, if PS5 only does 7m that's pretty horrendous. If like a million of those are actually just bought to ship to China that's even more horrendous. Most weeks are pretty terrible numbers for PS5 HW in Japan, with only the occasional decent week of 20k+. And of course software buying in Japan (at least physical) seems almost non-existent most of the time. Playstation is a dying brand in Japan.

With Xbox Series continuing to improve in Japan, Switch dominating, and at some point in PS5's lifecycle the next Nintendo system will come out and if it is anything like the Switch it will dominate Japan again. All these things point to PS5 not doing much better later on in Japan than it is now.

That is insane and there is no way a premium priced home console could ever sell that much in one year. The reason DS could do those numbers was partly because it was a relatively cheap handheld at the right time before mobile took off. Also DS could sell 7 to 8 million in Japan and the maximum that the PS5 could sell in one year in Japan would be 2 million which means it needs to sell 28 million outside of Japan to reach 30 million.

Produce is not sell or even ship. 30.5mil produced would be a few million less than that sold, but still a huge number. The remaing millions would be sold in the first months of the following fiscal year.

Lol 30.5m...where did that rumor come from?? That's hilarious. If PS5 can hit 20.5m in its peak year that'll be great for the system.

If we are talking about ps5 in a hardware conversation, i don't think alot of people are taking the fact that scalping of the system between 2021-2023 in Japan and the true sales of it afterward. Will ps5 sell more than 5mil? Almost guaranteed, 9mil-10mil? No chance. 7mil seems like a good target lifetime but that's only a partial explanation to what REALLY sold in japan.

There are 2mil+ ps5 consoles sold in Japan, out of those consoles how much of them  are actually in Japan? Does 7mil or around that justify the software sales that it will have? As of now the 2 things we know about but not how much is how many consoles are scalped and how much of the Japanese market is consumed by f2p games (like GI for example)

Software doesn't back it up in a positive light, we know FF and MHW2 will be exclusives (MHW2 I know XBS but its japan) but.... How much of those 2 franchises will decline from ps4 games? FFXV and MHW sold 1.5mil and 4.0mil respectively. What are you expecting from FF16 and MHW2? DQ will have a nsw or nsw2 sku, you think the split will be close and if so how come (we are talking about a multi million franchise)

PS5 will get P6, Both FFVIIR and I'm sure other big ga,es like KH4, etc. But that's not stopping the overall decline and I don't even think there will be 5mil ps5 lifetime that stay in japan (not to get confused with unique owners)