I feel like they might be going a bit overboard with video compression optimization. As an example, Star Trek Voyager in HD looks significantly worse than OTA 480i. On the plus side, it looks good in 4k.
https://variety.com/2020/digital/news/netflix-degrading-hd-v...
Even if they are bandwidth constrained, I wouldn't be surprised if some shows looked better at 480i/.5Mbps than 1080p/.5Mbps.