The so-called Blackwell GPUs should be twice as fast as the RTX 40 series.
Twice as fast and uses more force… 
This is of course pure guesswork (just like twice speed, by the way), but it’s what the trend is currently following.
For gaming, I see via Steam hwsurvey that the entire RTX 40 series doesn’t even have 1% market share. The most popular card is the 3060 card with more than 10% market share. The 3060/2060/1060 together account for over a quarter (25%+) of the total market share (and Nvidia hasn’t released an RTX 40 series equivalent to that, not in serial number and not in price.
Note: According to Steam hwsurvey, Nvidia has 80%+ of the GPU market. AMD and Intel together are less than 10% and no small detail is less than 10%.
The old (8.5 year old) GTX970 still has more cards in use than any RTX 4000 series, even twice as many as, say, the RTX 4070.
It is not only the economic downturn that has changed, but also the overall consumer PC hardware landscape that has changed, driven in part by the rising prices of the latest (high-end) CPU/GPU/mobo. With things like cloud streaming, a huge back catalog of good games that don’t require heavy hardware, plenty of good indie games, and even AAA publishers releasing games that don’t push your hardware to the limits. Will the user be less likely to see the need to purchase new hardware?
As Nvidia spreads things out, it can write off R&D over a longer period. A new GPU every three years. every two years. But the longer they do this, the more problems it creates for their server branch…