It plays faster, seeks faster, properly does Dolby Vision / HDR when the content has it and has different language subtitles. It animates properly from one screen to another (in stark contrast to Prime Video).
The content exploration and navigation is something to be desired, but comparing to other apps, it is on par (similarly bad).
I think Benedict's larger point is correct that I might put up with shitty Prime streaming because I want to watch what's on it. But it's not a delight. No way. And in the long term, that shit matters. The joylessness creeps up on you over time, until eventually you're left with Eclipse, Windows 10, or Android scrolling. Your NPS scores fall off a cliff, you get zero word of mouth, no lines outside of stores, nobody talking about it on social media/news/etc. and then everyone acts like it's some big shock.
It's not fun!!
I think Tesla, Apple, and Netflix all really get this.
God damn the software was shit. All the "car" part of it was fine (arguably excellent, even) but the rest was just. Ugh.
(four control surfaces to use cruise control?!)
The Tesla dashboard software package is just plain delightful, and that's such a huge part of cars now, it really matters.