Stereo cameras/camera arrays can have very large resolutions. An ML model is necessary for optimal results with stereo cameras, but it's more grounded in reality and verifiable versus a mono capture. With a large enough camera array, you can get precise, high resolution depth without ML, especially if you accept Gaussian splats, which use gradient descent but I wouldn't call them generative models in the same sense. Large, featureless, textureless planes are still a weakness however, while generative models can guess/interpolate values.

You can use a hybrid method with speckle projection/ToF/LIDAR (the first two behind mainly usable indoors) if you want to stay fully grounded though.