I wonder a bit if the ratings issue could also be seasonal. When we were all first locked down in March and April I was watching so much TV and Netflix, etc because I am in the Northeast and the weather was still meh around here so there was not much else to do. Now that we are in a phase where we can do outdoor activities with fewer restrictions most people I know are not watching nearly as much TV because everyone is trying to make the most of being outside while it is still possible. The NBA usually wraps things up by June so it is something people are used to watching TV in winter and spring not summer. People are trying to squeeze in as many outdoor activities as they can. Also a lot of the sports still feel super weird to me. It may just be because my team has been utterly terrible since the return but baseball especially has not held my interest at all. Between all the fits and starts with the teams who had COVID outbreaks at start of the season and wondering if it was all going to get shut down again any minute, I just have not paid much attention at all.
I have to say that my favorite thing about the NBA has been the content from the bubble rather than the games themselves. LOL