Yet in modern computer games, modern graphics cards denoise a scene in real-time at 60 frames per second using machine learning models [1][2] while doing all the other rendering at the same time. Granted, that's ray tracing, and the resolution is lower, and they technically cheat by using additional information, but it might be that DXO is not optimized very well.

1: https://blogs.nvidia.com/blog/ai-decoded-ray-reconstruction/

2: https://gpuopen.com/amd-fsr-rayregeneration/