It won't be a PC handheld; you need to drop this. It's ridiculous. Why would SIE make a handheld that doesn't run the same OS as their own home console? And for what exactly, a hypothetical launcher on PC (likely Windows)?
You're jumping through a lot of loops to avoid the obvious. As to your claims a portable with PS5-level specs can't be done by the time they ready a PS6?...
That's a single guy making a DIY portable PS5. Yes, not "portable" like a Switch or Steam Deck, but it's still a portable. Now imagine the company that actually created the system itself and has a history of manufacturing electronics, condensing that even further into a smaller unit by 2028. And you're doubting they'd be able to do it? You sound like the Xbox fanboys who were calling the PS5 a fire hazard back before it launched.
Also your idea suggesting they'd allow Other OS on a PS portable doesn't make any sense, same as suggesting they'd go out of their way to make the portable run an PC OS like Windows instead of the FreeBSD-based OS of their PlayStation consoles. All of this to push a PC launcher, would be incredibly foolish. They can't guarantee 3P will support the launcher like they do the console, and they can't guarantee PC gamers or even customers of a PS PC portable would focus their purchases to that launcher. Since with your suggestion, they'd just as easily be able to access Steam and keep the vast majority of their active time and spending there, meaning SIE could only count on upfront profits from the portable itself, increasing MSRP and lowering the amount of units they'd manufacture for sale.
A PC handheld would work for Microsoft since they also own the OS that vast majority of PC gaming is done on, Windows, in addition to Microsoft Store, the main standard for game development on PC that all engines support (DX12U), and PC Game Pass. Meanwhile, Xbox OS is basically a modified Windows. Sony & SIE don't have any of those vested interests, and at
best their launcher would be maybe 3 years old by the time a PC portable from SIE was ready to launch. Which isn't enough time to establish market share to guarantee some built-in early adoption of a PC portable.
Even if it were, the synergy between the portable and console would be lost since the portable'd be running not just Windows, but other OSes like Steam OS, whereas the PS6 would be running the PS OS. Why would you want SIE to actively damage synergy between their gaming products and create complications that'd mirror what the PS4 & PS Vita had to go through?
A PS portable only works if it's running the same OS as the console itself, and targets compatibility with the console's library, not some PC launcher's. It doesn't need an Other OS option which would just open up questions as to why the PS6 itself doesn't have Other OS too. It doesn't need to avoid creating complications through avoiding need for its own software library, only to create other complications through running a different kernel and OS than the home console (especially kernels & OSes that SIE don't even own).
Besides, you're ignoring that tech like PSSR and other hardware accelerated features would be shared between the PS portable and future systems like PS6, and it won't be difficult to find ways to cost-reduce for a portable at PS5 spec (i.e using GDDR6W instead of GDDR6 to save on chip count & power consumption, switch to small m.2 internal SSD instead of the internal SSD setup PS5s use, combine ASICs within the I/O subsystem for cost reduction, use more energy-efficient Zen & RDNA/UDNA architectures running Zen 2 & RDNA2 in BC, etc.). If anything, targeting base PS5 spec for a new handheld would be preferential towards running adequately scaled-down versions of PS6 games on it, if SIE can develop technologies (alongside with AMD) to automate performance optimizations across different target profiles.
Your idea of a PC-based PS handheld is at
best a couple generations too early. The things you suggest for it make no sense unless they also push that for the PS6, but there is no genuine reason for SIE to prioritize things like Other OS, or access to alternative storefronts, with their gaming systems. The reason Microsoft will very likely have alternative storefronts with next Xbox systems is because they need it in order for Xbox to survive as gaming hardware commercially. They can bring support for Windows programs on it because they own Windows and Xbox OS is already just an OS on a modified Windows kernel. OTOH, PlayStation's doing just fine prioritizing its own OS, and prioritizing the console. They don't even
really need a PC launcher IMHO but if they feel that's worth doing, at least it'd make their PC strategy more synergized (but only if they don't get any further in deep with supporting Steam than they already are).
Also
@mibu no ookami ...wake me up when Disney starts putting their MCU shows & films wholesale on Netflix and HBO MAX. Don't act like content differentiation (exclusivity) doesn't matter.
...better yet, wake me up when Microsoft decides to let Sony, Apple, Google or Tencent share IP ownership rights to the Windows kernel & OS. Hell will freeze over before that happens and you know it. So tell me why exclusivity is bad/nonimportant to customers, yet corporations swear by it?