A beefed-up PS4 is not a PS5.
The Switch 2 is Gen 9.5 hardware. technologically similar in architecture features to a PS5 Pro. Graphics performance is always tunable by developers, and for a handheld, what the Switch 2 delivers is more than sufficient. And Nintendo can boost GPU performance by 40% or allow developers access to an extra 1GB at any time.
On top of that, Nintendo could request a Switch 2 Pro from Nvidia, a process port with minor tweaks would 3x the GPU performance.
PS5 will likely see support through 2034 or beyond. There's no reason to expect Switch 2's support lifecycle to be any shorter.
The Series S's real problem is memory. It's 8-8.5GB of usable RAM is already behind the Switch 2's 9GB and well behind the PS5's 12.5GB.
RDNA2 being underwhelming is a common feature of all Gen 9 consoles (even though Microsoft's memory/GPU configuration choices made it worse).
Ok so u agree with me here that switch2 hardware wise is well(roughly 2,5x slower) below base ps5.
2028 and onwards when we enter x-gen period amount of ports switch2 gonna get will vastly depend on how popular it is at that point, if it will go on the trajectory similar(bit better or even bit worse) to og switch it will 4sure receive multiplat ports left and right, the question is tho what OP asked- about its secret sauce- how much and if any improvement we can expect vs what we got today, graphics wise, and gotta be honest here not much or nothing at all(unless its at heavy cost off lowering resolution and framerate).
Series S has many problems, ram being one of huge ones obviously, another being weak sales/its owners barely buying any new games, another one being digital only, combined with super tiny ssd, and last but not least of its problems, gpu 3x weaker from series x(roughly 2,5x from base ps5) and based on old and for sure extremly outdated rdna2 amd archi, especially by 2028
Base ps5 will get very long support but if u thinking 2034 u are largery mistaken(unless u mean legacy versions of sports games, but who cares about that shit on hc gaming forum like GAF

).
2030 to 2032 is time when most of AAA multiplat support will end, even for very succesful platform like ps5- ofc assuming we getting brand new ps6 holidays 2027- hopefully we will.
I say even if we get some big AAA multiplat port in 2032 that version gonna look and perform terrible, likely 30fps only, huge visual downgrade(especially when it comes to rt and ai upscaling, ps6 will be much more superior in those 2 aspects) so u gonna need to brace urself for similar experience that lowend pc users get when they chose settings well below console equivalent(aka low/very low)- games (compared to midrange gaming pc or brand new console) gonna look and perform artiociously, u will look at those versions and be like:
Lets not forget we got example of how such a late lastgen downgraded port looks and runs, of proper AAA game too: