Yes and no. They can't broadcast in 4K but they can stream in 4K, since every episode is these days also available online a few hours after the original airing. But the OTA's, with few exceptions, choose not to do that, mostly likely due to the higher cost of 4K production and their familiarity with Alexa's workflow.... Broadcasters are a the mercy of the fixed bandwidth they have available to send their signal and face a whole different set of problems than Netflix, Hulu etc. when it comes to 1080/4k.
Obviously, the Netflix technical staff disagrees that the problem is as severe as you deem it to be.The magenta vignetting is a hardware problem, as is the aliasing. You can't fix that just because it's RAW. That's not to mention the color science which has a strong cyan magenta bias...