The obvious: At-home TV viewing grew because the pandemic drove people indoors. The not-so-obvious: Traditional TV networks are not participating in those better in-home viewer growth trends.

Broadcast and cable TV erosion is accelerating -- at least via traditional measures. Nielsen’s prime-time broadcast viewing is down 20% to 24% or more in the fourth and first quarter, looking at live program/same day rating.

We expect double-digit percentage erosion declines. But a year before, they were in the 12% to 15% range. One possible answer, at least since October: There are also far fewer prime-time original shows then a year ago.

Another factor is that Nielsen has been lax in serving its TV panel homes, due to pandemic issues where its field agents couldn’t get into homes. That’s important, says research analysts, making sure equipment and residents are using that equipment properly.

Nielsen says while it is true field agents haven’t had in-home access, they have been doing other stuff remotely. In addition it started in-home service again this past March. And, most importantly, it says ratings, demographics and other measures really haven’t changed. So no foul, right?

Brad Adgate, veteran media agency research executive, now a media consultant says: “There could be an issue of fatigue.” In particular, this could include a range of things.

While a TV panel home may have the TV set on, people in the home aren’t always correctly pressing Nielsen People Meter remote controls. This lets Nielsen know who is actually watching, which then results in tabulation of demographic audience data.

Still, last week, the VAB blasted Nielsen for its relative lack of attention to these homes. One indication: The number of homes in Nielsen’s panel not watching “TV of any type.” This has grown to 4,642 in February 2021 from 2,735 in February 2020.

What’s going on here? Broken TV sets? Too much work outside the home? Weather related incidents, tornadoes, hurricanes, snow storms?

Data can be vague. But opinions can be specific and pointed.

For example, there were 17 million Nielsen-measured average viewers watching the NCAA’s March Madness championship game last Monday night on CBS. Two years ago, there were 19.6 million for the big game.

Did all those 2.6 million go to streaming platforms to watch the game? (One major streaming platform distribution would like you to believe so.) Maybe time was spent watching more TV reruns of long-gone crime procedural dramas. Maybe those viewers turned to political podcasts.

Down the line, we can imagine a more precise postmortem will be revealed, explaining what really happened in the pandemic.