In the not to distant past, movie studios were not allowed to own movie theatres. The FTC was very wary of large companies using vertical integration to take over the market and keep movies from smaller companies from being shown.
What you're seeing here is the future. Amazon produces the movies, finances the movies, distributes the movies, controls how they're reviewed (they also own IMDB).
I didn't know the Paramount decree was ended, but I guess it was put in a two year sunset period two years ago so it is indeed gone. That's a shame, it's hilarious that the FTC doesn't think the studios could bring back the old studio system. Doing that might be the only thing that'll save mainstream theatres from Blockbuster's fate tbh.
We really desperately need a similar ruling for streaming services though.
What you're seeing here is the future. Amazon produces the movies, finances the movies, distributes the movies, controls how they're reviewed (they also own IMDB).
Oligarchs never trust what they don't own.