I understand the frustration.... but I doubt looking to OBS to address this is the right approach.
What you are suggesting would require the streaming platform (YouTube in this case) to have a reliable API/interface that can be called/monitored for streaming status, and that streaming s/w (OBS) be updated to utilize that. For example, I run a live stream using OBS to Facebook. Facebook's live producer sometimes indicates a stream problem when the stream is actually working fine.
OBS's indicator is telling you if it has a connection to a server, and is receiving the appropriate acknowledgements. After that, it is up to streaming host/platform how it handles the stream you are sending (I don't see how OBS could do a thing about it short of something along the lines of a reset/start anew, or ??)
Personally, I almost always have the stream platform monitoring page up (/Live/Producer in my case) AND either I or someone I'm in direct communication with, watching the stream on a separate Internet connection (ex tablet using cellular connection). LOTS of things can happen/go wrong that have NOTHING to do with OBS's stream and its connection to the streaming host, and I'd question the reasonableness of asking a free software platform to monitor all that other for a streamer. I've had issues with my Internet connection (which OBS promptly tells me about with indicator going from Green to Yellow to Red, and disconnects, with prompt re-connects), the security or similar software on a corporate laptop interfering, etc. But with Facebook at least, I personally have never had the issue of OBS saying stream OK and that not being the case
Now if the industry came up with some standards for such stream status/monitoring, then......
Then again, I'm a relative newbie to OBS, and maybe there is something I'm not aware
