AMD GPUs are good enough, cheaper, and actually available for purchase. I also appreciate that they have good open source drivers and don't need any fiddling to get working on linux and BSDs.

Is this reason specific to game development?

No, just as a consumer, but developers are building products for sale, which means they need to target something near the lowest common denominator, which should lead them to a similar conclusion.

I wouldn’t say that AMD is “doing better” than Nvidia in the gaming market but as another commenter said, their success is probably mostly due to an excellent price/performance ratio compared to NVidia.

Intel is also somewhat making ground with their Arc GPUs.

The key to doing well in the gaming market are good prices, and good gaming performance with DirectX and Vulkan.

Their market share is 12%, I’m not sure how that translates to “doing well”. Nvidia is 84%.

Intel has been chipping at Nvidia and AMD has been pretty flat.

https://wccftech.com/gpu-shipments-continued-to-decline-in-q...

Games indeed do not use CUDA. I wouldn't say AMD is doing great in gaming GPUs but at least their GPUs work so they're not locked out of the market. AMD tends to give better price/performance.

I see. What frameworks do game developers use? Are they custom and different for each game?

DirectX or Vulkan

Cheaper cards with more memory that work at least well enough for the games available. Its been easier to get AMD cards for a while now. More options in stock, more consistently; at least to my casual observations.

Reason not mentioned in the comments already there: NVIDIA has explicitly stated in the past that a lot of the graphical performance in games is expected to come from DLSS. You may have noticed that the raw power of cards is not going up as much as it used to (especially on the lower end), well NVIDIA is arguing that the performance gains will be made up by DLSS.

When it was initially released it required a lot of interaction between NVIDIA and the developer to fine tune the model to the particular game, and most didn't care enough to do it. Now I think there are some ways for developers to mess around with DLSS on their own but due to the state of modern game development most simply don't care enough about it.

So a supposedly very large advantage of NVIDIA cards simply doesn't exist in most titles as of today(most titles do have the DLSS option in the settings, but in about 80% of the titles the differences are negligible).

I have to use DLSS for "new" games that haven't had driver updates or optimization because of a rush to market. It works "ok", but i notice it a lot on detailed effects, which can make a game that is already bland and boring looking, become irritating.

I don't and probably won't game at 4K - foreseeably. FHD here.

I can go buy a new AMD card right now with decent performance for gaming for a decent price.

I can also go buy an intel ARC GPU with 16GB vram, for an even decenter price.

For comparable prices to above, a moderately weak nvidia (3060, 12GB), used, probably for crypto mining, so warranty probably voided even on "2nd hand warranty" brands. If you need compute cheap, used nvidia. if you want current gen gaming for the same price, amd, and with a measured attitude, intel ARC.

Not just for data centers, but for hash cracking too, the latest 4090 is the best right now in the market, going lower than that, you might find AMD is best price/performance ratio. I can’t say anything about gaming as I’m not a gamer myself.