Amazon Prime in 1080p looks to have a higher bitrate when played through the app on the Sony X-800 UHD player.
I agree that Netflix (at least in the US) has gone to utter doggy poo. Especially in content offerings, they once had tons of 70/80/90s titles and obscure/Z grade stuff with good HD masters. Now, it's just "Netflix Originals" like Stranger Things, Hilda, and cringy twerking movies.