NVIDIA is quick to acknowledge that the benefits aren't quite as dramatic at higher resolutions (where you run into bottlenecks), but you should still see improvements at 4K. Keep in mind that the company is also using its latest graphics tech mated to a recent Core i9 processor -- you might not see such dramatic results if your system is more modest.
There are, however, some improvements that are more universal. There's now a beta Ultra-Low Latency mode for DirectX 9 and DirectX 11 games that only submits image frames just in time for rendering, delivering high responsiveness without forcing you to lower graphics settings or buy new hardware. You'll see the most benefit in GPU-dependent games where frame rates are between 60FPS to 100FPS, but it could be vital for any reflex-sensitive titles.
Other tweaks? There's now sharper integer-based graphics scaling for classic 2D and pixel art games (think emulators or retro-looking titles like Hotline Miami) if you have an RTX or GTX 16-series card. There's also a new Freestyle filter, Sharpen, that's both more effective than the current Detail filter and half as demanding on your GPU. This latest driver also brings 30-bit color support to all of NVIDIA's hardware lineup, support for the newest G-Sync monitors and optimized settings for more games, including Wolfenstein: Youngblood and Bloodstained. You'll likely want to install these drivers, then, no matter what exact GPU you have or what you intend to play.