I think people are just frustrated to see players make so much money. Remember that the NBA viewership is the whole planet, not just the USA.
I listed to talk radio. This whole summer, it has been all NBA. Nobody even knows if the MLB is playing. NFL training camp has started, and the conversation on ESPN/FS1 or even local sport is: Kyrie, LeBron, Steph, KD, LaVar Ball, ... etc.
You check out youtube channels, NBA stories gets the most clicks.
LeBron reign will soon be over. People would like to know, who the next king of the NBA will be.
NBA Franchises selling for 1.5+billion (bought at 85millions 20 years ago) and there are buyers from the whole world lined up to pay that money.
The most recent NBA draft was the best in a generation with talent after talent after talent ...
Seriously, what are people talking about?
Maybe the pace of growth won't continue, but the NBA will continue to grow.