Do love some console speculation stuff
I'm not going to focus on hardline specs per-se, but I think 10th-gen consoles
NEED the following things to be powerful, cheap, energy-efficient, and differentiate themselves from other commodity electronic devices (PC, mobile, tablet) for a decade or so, leveraging the design strengths consoles have always had over those other devices:
>Chiplet-based GPU and CPU designs
>PIM (Processing-In-Memory) and PNM (Processing-Near-Memory) architecture designs. PIM results have shown over 70% performance increases in certain workloads in data center applications, and Samsung are already making HBM and DRAM PIM memory modules. Their HBM2-PIM modules can provide over 1 TF of compute per module in the memory stack.
>PIM will be more important going into the future to help massively cut down on energy consumption costs with moving data over the memory bus. PNM designs already exist in limited forms with the current consoles (SSD I/O subsystems in Xbox Series & (even more so) PS5 for example), but further features of DPUs (Data Processing Units) can be added and coupled with PIM designs for huge perf gains at minimum power consumption increases (along with chiplet-based designs of course).
>QOL boosts with Southbridge integration into DPU-style data logic block featuring data compression/decompression.
>HBM-based memory. Ditch GDDR, it's getting long in the tooth and limiting.
>GPU/CPU architectures built around PIM (can be done when combined with chiplet approach). Will allow for much better processing locality of data, saving on data movement around the system, significantly saving on power consumption.
>Entry-level VR/AR headsets included default with all systems. Doesn't have to be anything super-fancy, but serviceable.
>Optional VR/AR-based OS UI for user navigation
>Haptic feedback analog sticks
>Ditch disc support; move to cheap, decent-speed (60 MB/s - 80 MB/s) 64 GB microSD cards for physical medium. Have microSDs interface with data decompression hardware to boost throughput.
>1 TB - 2 TB SSDs with bandwidth support of between 16 GB/s - 32 GB/s
Those are the general things I feel the 10th-gen consoles need to shoot for. CPU and GPU specs will be whatever's economical for their timeframe, but I DO think they'll be handily more powerful than a 3080 Ti in all aspects, can't imagine 2027 - 2028 consoles only reaching GPU perf of a 2020 PC GPU, could be a pretty bad look.
But really, CPU & GPU designs (personally I think CPU design would take an approach of more plentiful smaller cores organized closer to specific memory and graphical logic for data locality purposes, with a few larger normal cores with the more traditional setup) are secondary compared to making sure PIM & PNM are present, basic VR/AR is standard, HBM is standard etc.
Also I think Sony and Microsoft's design would diverge in some big areas for what their true market goals would most likely be, but the big things, they'd share in common. I could probably expand on that sometime in the near future.