It's also just not factually true:
TNG towards the end (when it was arguably going downhill) was still rated higher than DS9's when they were both on the air (when DS9 was something new and fresh).
It's not like there was a massive upheaval in media viewing between 1993 and 1999 anyway. There were slightly more channels on at the end of the decade than at the beginning, and there probably wasn't one cable market that got enough of the new ones to matter. If 100 new channels signed on, any individual market only got a handful of them.

TNG towards the end (when it was arguably going downhill) was still rated higher than DS9's when they were both on the air (when DS9 was something new and fresh).
It's not like there was a massive upheaval in media viewing between 1993 and 1999 anyway. There were slightly more channels on at the end of the decade than at the beginning, and there probably wasn't one cable market that got enough of the new ones to matter. If 100 new channels signed on, any individual market only got a handful of them.