To give DarkTable credit, neural-network-based denoising will be in the next major release (5.6).

And even without neural networks, DarkTable denoising is better than open-source competitors, due to the database of camera sensor noise shipped with it. For each supported camera and ISO setting, it contains the measured values of Poissonian and Gaussian components of the sensor noise, so proper denoising becomes a one-click operation. That's as opposed to the much more complicated "drag the luminance and chrominance noise sliders until the noise disappears, then drag two more sliders to recover detail" workflow found, e.g., in ART.