One thing not really mentioned is in threads is...software. Every soundcard used to compete by trying to offer better 3d or better effects processing than the others. Game developes had a half dozen sound sdk's they could write their game audio for (EAX, Aureal... I dunno there's probably at least half a dozen). Cards competed on features. In the pro segments, literal megabytes of midi sample space & dsp coprocessors attracted audiences. Each of these tended to have one of any number of software toolkits... so you needed games or apps to all get onboard too. Many SDKs had software fallbacks so many users would even care that they didnt have Aureal3D support or whatever.

The actual advantages of doing things in hardware quickly faded, as cpus became ever more powerful. But just as much, the various apis didnt really ascend, or their technologies (head-related transfer function) got swallowed/mainstreamed. Namely DirectSound3D (1996), which grew various hardware offloads (EAX), and eventually because DirectX Audio. The pressure to compete deflated under thus mainstreamification... few people wanted to the extra 100 miles to support bespoken fancy hardware capabilities 0.01% of gamers might have, when they got 90% there using the common denominator.

I dont actually know what folks like gamedevs do now. Both Xbox & Playstation say they tick a lot of really good 3d audio boxes, they support an array of common 3d audio standards that I dont really know that much about. I'd love to know more about hoe the gamedevs feature-sets & capabilities have evolved over time... most coverage is alas ultra consumer facing & abstract; getting some intimicacy with technically what is possible now vs then would be fascinating.

I do think Creative has continued doing some refinement on their dedicated cards, but, like, in general, I think the other answer to the question is just that we are damned near perfection. We have really smart folk telling us we're making things worse by having too high a sample rate (>=192kHz, see Monty's https://people.xiph.org/~xiphmont/demo/neil-young.html & newer excellent audio myth videos), there's so little noise left to chase out to drive SNR higher, THD is tiny. Many laptops & gaming motherboards have really really good audio outputs, which are like $4 more cost for the person making the system for nearly flawless output, and even cheap stuff has gotten quite fine (but boy can engineers still cut corners & create trashfire designs, especially on low end systems, but it's gotten harder!).

What's kind of exciting in the past half decade is that Intel realized that on-card processing needed effective commodification if it was to survive. Each chip/driver maker making their own bespoke solutions like back the 90s was going nowhere & the only effective pushback against forever doing more & more on the cpu was to make the sounnd hardware more usable, easier to implement consistently & well. To that end, they did the amazing working of making SOF (sound open firmware) which is an implementable reference firmware anyone can use & ship for sound devices. It's a community effort now, to make a orchestrator/controller that implement commom driver interfaces, & figures out how to use a slate of DSPs effectively to do thr job, which under the hood is what soundcards have been. Now everyone can work together to use these DSPs effectively & well, whatever chips eith ehatever DSPs on them you happen to have. AMD is one other noted user, I forget who else.

https://thesofproject.github.io/latest/introduction/index.ht...