Why to a smaller extent?. Like you said PC is taking off big in japan and portable PC's are going to be helping even more with this.

This is going to effect both Sony and MS in the japan market since Pc is getting all their games (Even if Sony ones come later people still now know they will come). Its getting all the japanese games thats on both consoles including Switch. Honestly the only company Pc getting huge in japan wont effect is Nintendo since they still have full on exclusives.

Because:

1. Like you said many games release on PS before they get ported to PC. The latest couple of examples are FF16 and 7 Rebirth, which aren't even 1st party. Most people would like to get their hands on them during their first year. The exceptions are the rare games that have long legs, typically from Nintendo. The majority of notable timed exclusives will sell a lot better on Playstation, because most people either prefer them on Playstation, don't have a decent PC, or simply won't bother to wait for the PC release. Hence FF7 Remake sold like shit on PC even though it was a timed exclusive since announcement. The average fan won't "wait".

2. The Playstation brand is on a different league from Xbox. It can sustain itself longer.

3. Playstation remains bigger than PC in Japan when it comes to the more notable releases. This can be extrapolated from sellers like Elden Ring where a comparison between official shipment figures and retail sales could be made. Elden Ring on PS dominated the PC version at launch.

4. In Japan, PS5 is selling a lot better than PS3 and PS4. China is traditionally and heavily PC biased, so I don't think the "PS5s are probably being exported to China" helps your case here lol. The fact is Playstation is growing almost everywhere despite PC's rapid growth. If this changes and PC starts impacting Playstation sales more clearly, Sony would (or should) reconsider their strategy and adjust their plans.

Xbox is also growing in Japan (could mostly be attributed to the Xbox One being near non-existent), but its growth could have been bigger if it wasn't just a poor man's PC. PS might be heading there too, but their approach is logically not as harmful to console sales. Xbox does hilariously little to distinguish itself from PC. PS does just about enough to sustain its relevance and momentum.

I have a few problems here as your kinda changing the point i was making.

1. Not many games release on PS before PC. Other than some FF games what released on PS that has not come to PC?. In fact the return is also true as PC gets some console exclusives thats not on PS but is on Switch before they come to PS consoles. The new CEO of SE has stated he will be moving away from them timed deals. As you can see FF7Remake part 2 is only 3 months exclusive.

FF7 remake sold like shit on PC for a number of reasons. It was a very bad bare bone port that launched as an Epic Store exclusive for full price.

2. No one said otherwise. Again this is not the original point.

3. For now. But with the rate PC is growing how long will that remain before it does effect Sony?. Just look where most 3rd party sales come from now. Capcom and other devs are having record sales on PC.

4. I didnt say anything about this?. I never even mentioned China or PS5's getting shipped there so i dont get this last point.

I believe in the US, Xbox 360 was the winner of its gen, which is really saying something. If you can beat the Wii and Sony and claim the top spot in that territory, wow. But it also shows you just how US-centric that brand has always been. In Japan, it's a distant memory the moment it launches. In the EU, same thing. I think it's strong in the UK, but still behind the others. So for anyone to be disparaging them for their Japanese performance, I don't think they're looking at it correctly. As much as Microsoft would love to be the top dog everywhere, they just aren't, and never will be. Their turf is the US, and to a lesser extent, the EU. Japan is an afterthought. Mostly because it's a lost cause.

Well Xbox Series X/S crossed the half a million mark in japan according to Famitsu. When you compared to the other Xbox Consoles sold in Japan is the second best.

It's very difficult to compare raw numbers. How much growth has the industry seen since 2005? How many more people play games? Per inflation, how do the two consoles relate MSRP? What is the per-capita player-count? A lot would need to be analyzed.

You have it backwards. Trying to to factor inflation, msrp, industry growth ect. that is difficult.  Comparing raw numbers is easy.

Easy, but woefully inaccurate. That's why comparing things from different eras is super tricky. Too many variables. 

According to Famitsu in the latest week Xbox Series X|S sold more units than PS5 and PS4 combined.

Famitsu Sales: Week 45, 2023 (Oct 30 - Nov 05)

A rare event for sure, but only due to the lack of the PS5 stock.  Series consoles sales uptick from last week and last years numbers are good.  Xbox still has a long ways to go, to building a strong foundation to grow on.  And it does appear that with many of the recent moves, they're in it for the long haul.