Here's something no one has mentioned yet.
Games need RAM also. Not just vram.
Games now days on the PC use how much ram? 8, 9 - 10GB?
So the consoles have to share the 16GB of RAM they have between system ram and VRAM.
A gaming PC with a 3080 would have 10GB of DEDICATED super fast VRAM and usually 16GB of system ram.
So your PC suddenly looks like it has a lot more ram than a next gen console.
That's true but it doesn't so much matter because consoles only do one thing: game. There's a lot of efficiency to the process that gets added by virtue of them being closed systems & limited in the number of specs available (let's say 3 this gen - PS5, XSX & XSS). There's also different builds & APIs for each, and then for PC as well, so I wouldn't count 10 GB in a console as 10 GB in a PC - it's going to depend a lot on the devs in order to reach that parity.