They could have put an ATSC modulator in there but I think those used to be very expensive - hmm, even now when I search for those I see $250 - $500 price tags vs $20 for NTSC. But then you still need a cable connection at both ends and I think those are actually not that common overall - they seemed to become common-ish on new homes built from 1985 to around 2000 but newer homes are more likely to be wired for ethernet and/or fiber and older homes have nothing.
The world has been shifting to internet-first with TV as kind of an afterthought, or something that just comes along for "free" once the internet is good enough, whereas in 1980, everyone had TV and you got your internet through a dial up modem (if at all.)