iTunes bitrates on Apple TV app(firestick/roku) vs Apple TV 4k
I was under the impression that apple TV+ and iTunes had one of the best quality streaming at 4k. I recently bought Lord of the Rings and Hobbit extended trilogies. As I started watching on the apple TV app on roku, the quality really wasn't that great; can tell it's 4k at times, but is quite blurry and smeary looking, black level not great, without seeing any grain. I setup my firestick 4k with ability to show bitrate, and to my dismay, the bitrate was only capping out at 15mps, 12mpbs more often. I loaded lord of the rings on amazon, and it was staying around 10-12 in stills and peaking at 25 mbps.
I don't have an apple TV 4k to compare, but I have done enough research online that shows iTunes films regularly peak at around 30mbps on the apple TV 4k. Does anyone have any experience, opinion or evidence that the Apple Tv app on third-party devices have significantly lower 4k quality compared to other services like amazon, Netflix, or Disney+.
I feel like it is almost false advertising or manipulative to lower the quality on third party devices. Couldn't they serve the same quality stream to all devices, and let the Apple TV stand on it's own feet, without having to artificially lower quality on other devices. Either way, isn't the company shooting it's self in the foot, by showing inferior quality when using these other devices.
Photo below Is from Amazon on firestick 4k using hdr10+
Photo Below is Apple TV on firestick 4k using dolby vision
FireTVStick4K(2018)/Soundbar(2019),