Thanks to AMD, Sony and MS are going head-to-head, and each needs to be the 'winner'. This competition is going to 'up-spec' each machine more than would have been the case in earlier times.
But there is a limit of how high either can go.
AMD's core new tech is 4-chiplets around an I/O die. Each chiplet can be a CPU or GPU cluster. One chiplet should push close to a 1080TI (2080) in performance, or hold 8 zen2 cores. Of course this manufacturing option is not an APU- but the use of AMD APUs for consoles is a new thing- a console like the PS2 was loaded with various CPU and GPU chips.
An APU is 'cheap'. Going to seperate GPU and CPU chips (like a PC today) is more expensive (and unlikely now). Going to AMD's full-on 4-spot chiplet solution is expensive, but its a 'one socket' (yeah, I know sockets ain't used on consoles) solution. And one entity to cool.
However, if either Sony or MS goes too crazy, it delays their console and allows the 'enemy' to release first (basic 7nm next gen console can hit Xmas season 2019 trivially). MS is gimmick-free this time- Sony has a state-of-the-art VR solution as an option.
I think Sony will go GPU-per-eye, and have the two GPUs work together for non-VR gaming. MS should go one big fat GPU- probably significantly better than 1080TI level. And both companies, if they use basic 7nm, can have improved versions of their consoles within 2-3 years on the tweaked 7nm process. If either were insane, and delayed to next year, they'd be on a tweaked process with nowhere guaranteed to go after that for years and years- for the next true process shrink after 7nm isn't even on the horizon yet.
The only reason for the crazy speculation today- and claims of 2020 release, is because AMD has yet to release Zen2 and Navi on the PC side. Yet a little history teaches us AMD always gets its new tech ready and perfected for consoles first (much to the frustration of AMD PC gaming fans). AMD has been partnering MS and Sony with Navi tech *and* their GPU tech after Navi for several years now. PS5 and Xbox Next will have Navi+ while the first discrete PC navi cards will be vanilla first gen Navi - that's just how AMD chooses to roll.
And talking of History, the dreadful specs of the Xbox One is something MS is determined to never repeat. Dreadful incompetence at MS (linked to their focus on Kinect and always on spying) allowed Sony to get all the good AMD tech for the PS4, while MS engineering 'geniuses' forced AMD to use that hopeless discrete GPU RAM chip they were so proud of.
Today MS is as anti-gimmick as possible, and wants a plain gaming super system. MS even killed of its VR gaming projects to keep this pure focus. Xbox Next has one design goal- to be faster than the PS5 in conventional 4K gaming. MS wants Sony's VR fixation to cost it the plain gaming crown. In other words as it is today with the 1X crushing the pro.
Until we can get our hands on AMD's PC zen2 and navi- also made at TSMC for the first time- we don't have a proper guide to the reach of AMD's new tech. And there is still the outside chance that something is wrong with AMD's new tech on 7nm. But given this isn't the case, I think most people here will be shocked at just how ambitious both MS and Sony are with their new consoles.