I don't think that's true. The GPU architecture is much better so it is actually a better GPU overall. The RAM is GDDR6 which gives it an advantage, plus it has the SSD and a vastly superior CPU.That's why he mentioned next gen tricks. New features can work more efficiently.
But older games aren't likely to take advantage of the new architecture.
Remains to be seen how it ends up. GPUs are really complicated. Arithmetic compute is just one part of the puzzle, and I don't think we know how the rest lines up.
(Technically even that comes with a caveat that compute *can* be counted different ways. But I doubt it makes a big difference unless youre comparing really old GPUs to new ones)