Just seen the press about RTX 4000 series cards. From a pure financial greed perspective - why would nVidia even bother releasing them any time soon when they could just as easily manufacture a new batch of 3000 series cards and they'll still sell at 200% MSRP.
I can think of a few reasons:
Replacing the 3000 series with the 4000 series won't cost nvidia any additional money because the costs will have already been incurred and accounted for.
The profit margins on 4000 series cards will be at least as high as those on 3000 series cards, so nvidia will make at least as much money per sale from 4000 series as from 3000 series.
Some customers who would not buy a 3000 series card will buy a 4000 series card, so nvidia will sell more product with at least the same profit margin and thus increase profits further. Some of those additional sales will be existing owners of 3000 series cards upgrading and some will be people who have been waiting to buy a new card and will be tipped into buying one by a new generation. Either way, there will be some additional sales from releasing the 4000 series.
Part of the graphics/mining card market is image. A large part. The image of being cutting edge matters. Neither AMD nor nvidia can afford to have nothing new when the other one has something new. That would lower their relative image.
Development is an ongoing process in the GPU market (and many other tech markets). It would be more expensive to put it on hold if a company wants to remain competitive. If nvidia stops development for a year, they'd be a year behind the market. Playing catch-up would be very expensive indeed. They'd also lose some key staff. Even if they continued to pay their chip development staff while not wanting any work from them (which would go against the idea of cutting costs), some of those staff would leave anyway because they want to be working in chip development. So they'd be working for a competitor - a double loss for nvidia.
I think it's more a question of why would nvidia
not bother with releasing the 4000 series. They have nothing to gain by doing so and plenty to lose.