When streaming started to become a thing, and it became incorporated into the Billboard hits ranking algorithm, hit songs started to stay at the top a lot longer than they used to. The reason was exactly what you pointed to. Industry marketing campaigns would be push songs on TV and radio to the top spot in order to drive sales, then drop the campaign immediately for the next song to push. When listeners started to have more control over the music they listened to, they didn't hyper-cycle like the marketers wanted. I would assume the marketers have adjusted to the new listening model, but I haven't kept up.