JPEG does nothing of the sort filter wise.
Did you look at the specification images on the netflix blog from it in action on netflix?
While this is good for low quality, as it's better than blocks, the same is also employed in their high-bitrate example which is unacceptable of an art medium like film, and should be as close to the source as possible, which the JPEG accomplishes, albeit with some noticeable blocking. However, the detail of the scene is preserved. It would destroy partical grain effects. What if the barn is meant to look rustic and that smooth effect makes it look new. What if a lot with lot. Sand, dirty details, all will but smoothed and flat tone. In fact you can see blocking is still a thing, it's just being smoothed out with the filtering. The AI/Algorithm has issues with the tree branches on the right and tries to preserve them, showing the underlying blocked compression like JPEG.
Here is a side by side, you can clearly see the filter in action ridding the scene of detail and creating easily processed and streamed flat tones. It's in a ZIP because for some reason large PNGs have been failing in uploads lately for some reason.
