I think the consoles are going to produce games that look better than a 3090 can produce. Just wait until someone like Naughty Dog shows off what they've been working on for the PS5. Going to look phenomenal.
Doubt it very much this generation. Mostly because of Microsoft. The like 2 or 3 games in an entire generation that manage to impress on consoles (vs PC's, because of course there are more than 2 or 3 games that just look great) are ALWAYS the result of huge budgets from first party studios. It's not magical console optimization. They aren't magically going to grow new rendering cores. And a 3090 would certainly be able to play anything like that made for PC at better graphics settings/performance than a console ever could.
This is 99% budget where they can throw gigantic art departments at the game, where as most third party devs and publishers can't risk those types of budgets, except on the 1 or 2 sure fire sellers in a given generation (and even then they tend to spend those budgets on marketing and not game assets).
But this changes with Microsoft both being willing to support their developers with those budgets and time, AND having PC being part of the focus along side the Xbox. Hell, you can argue that the first next gen game (as in you couldn't play it on a current gen console) already came out, and it's a PC exclusive (Flight Simulator).
I think this gen we're going to see some Microsoft published games that are going to be looking great on an Xbox, and AMAZING on a PC (like most third party games do today).
On top of the usual third party games looking and running better on PC vs consoles (Especially when it comes to RT).
Anyhow, the statement isn't something new, Carmack has made this claim in the past. And it makes sense, when you have less variables to account for you can tailor make your game to the strengths of that particular hardware. Top PS4 exclusives look ridiculously good
If you're talking about that old quote from him, Carmack wasn't even talking about fixed hardware. He was mostly talking about high level API performance on PC.... back in the DX9 era. Not really relevant.
So what GPU is the XSX (and XSS) equivalent to?
In shader performance, we don't know. We won't know until these thigns are out. On paper it's probably close to a 2080.... but in real life performance other things come into play. I mean, think about that a 2080 is pulling almost as much power all by itself as an entire XSX. It's got a huge cooler just dedicated to the GPU. It's not sharing bandwidth with a CPU. On the other hand the RDNA2 GPU on the XSX is likely to have a different feature set... Just going by teraflops is not going to be very accurate. We have to wait and see.