Like if I stream netflix to a TV supporting Dolby Vision what format is the video being streamed in and is the TV manufacturer just paying Dolby for the right to correctly decode this HDR info then?
[1] https://forum.doom9.org/showthread.php?t=183479 [2] https://pastebin.com/m5NfUTbc
Since the format of this metadata is proprietary, the demuxers, decoders and displays need to understand it and properly apply it when rendering. That's the part that needs to be implemented and paid for.
But that's really not all of the technology - Dolby Vision isn't just the metadata format, it's also definition of how the videos are mastered and under which limitations (e.g. DV allows video to be stored in 12-bit per pixel format, allows mastering with up to 10.000 nits of brightness for white pixels and defines wider color range so better, brighter colors can be displayed by a panel capable of doing that).
https://www.elecard.com/page/article_hdr is actually a pretty good article that overviews this topic (although you do need a basic understading how digital video encoding works).
To see HDR content at its full dynamic range, you'll need an HDR-capable device or display. Viewers watching on non-HDR devices/displays will see an SDR¹ video derived from the HDR source.
¹ "Standard dynamic range" or "smooshed dynamic range"
Not exactly - you need an HDR Mastering display to see HDR content at full dynamic range. There are essentially no high volume consumer-level devices, with the exception of maybe Apple's XDR lineup (MBP, iPad, iPhone, Pro Display) with the capability of displaying non-windowed HDR content at full brightness.
Everything else relies on tone mapping, even the latest 2022 OLED & QDOLED TVs.
The entire points of Dolby Vision is that it should give you the same image no matter what display you display it on, if the device is capable of displaying it. It’s an absolute format of light and color values, rather than a format based on RGB values.