Does a dedicated sound card bring any benefit regarding creating a game?

I need to get a new PC. I haven’t had a dedicated sound card in longer than I can remember.
I’m not an “audiophile”; I also think my hearing is slowly degrading with age,
but anyway, I want to build a game, and since I’m going to be buying a new PC,
I thought it made sense to ask if a dedicated sound card brings any benefits for building the game,
like producing better quality when processing sounds files when compiling or something…

A dedicated soundcard will allow you to have less lag when recording, to start with. If you are only using virtual instruments that will not bring you much value.
On the other hand, if you’re going for a professional card with onboard processors, you will be able to run a lot more plugins than you would do with just your PC, but such kind of card is going to be way more expensive.

A dedicated sound “card” can be useful in a few instances:

  1. You need physical I/O that are different – balanced connectors, microphone pre-amps with phantom power, etc.
  2. You need high-quality drivers for digital audio software – ASIO drivers for CuBase or whatever.
  3. The sound quality of your built-in motherboard sound drives you crazy because it’s as noisy and grungy as $0.18 in Chinese components will buy.

The solution for 1) and 2) is to buy some “studio” hardware – which generally connects through USB, but could also be FireWire (rare) or PCI-Ex (rare.)
The solution for 3) is usually to buy an external USB DAC, or just a pair of USB headphones.

Modern Windows sound software mixes in 10 millisecond chunks at 48 kHz by default, (and there will be at least two of those buffers on the way out,) which means that latency will be “OK” for conferencing, playing games, watching videos, etc. Only if you use your computer for interactive music playing, will lower latency become important.
FWIW, I use a Microsoft LX-3000 USB headset for general computing, and development, and I use a Steinberg UR-22 with Sony MDR 7506 headphones and a Studio Projects B3 microphone for audio/music production. Most importantly, I make sure to develop and mix game audio on the USB headphones, to make sure that it sounds good on “consumer hardware,” and only fix up the top and bottom ends of sounds and mixes on the “high end” gear.

Personally, onboard processors have never seemed worth it to me. Get more cores in your CPU instead! Those cores can be used for sound processing, OR for building lighting, OR for rendering video. Threadripper is a thing!