I’m a huge proponent of physical media, but this is entirely unsurprising given Microsoft’s acquisition of Bethesda. Compared to Switch and especially Playstation, the Xbox has a much higher rate of digital game sales.
If Starfield were on PS5, it would get a disc release for sure, and Xbox would probably get one too for the sake of parity. But discs aren’t terribly important to the Xbox crowd, and that goes double for PC gamers.
Moreover, digital games are good for the publisher’s bottom line, so physical media is only going to exist as long as customers demand it. And PC and Xbox gamers simply don’t.