Replaygain works reasonably well for modern music, as do the LUFS units.

The problem with video content is there can be extended very quiet parts. If you try to bring the “average” volume of an ad to the same “average” volume as the last 30 minutes of a drama it could end up being insanely low. The average level of the drama being low due to long quiet parts.

Not always the case but this problem isn’t as simple as it might seem.

My main hope is that this doesn’t kick off a “loudness war” for tv/movie content on streaming in an effort to get its average volume up as high as the ads.