I'm a heavy YouTube consumer and this just seems like a headache with extra steps/complication, while shooting features like live streaming + chat in the head. Also it's a normal use case to view videos in your browser.
I rarely view livestreams, nor use chats. I don't know if there are alternatives to either.
Using mps-youtube to search, curate, manage, and play lists of videos, without relying on YouTube's server-side management is a real bonus.
Hooking mpv into the stream more smoothly would be useful, and I don't have a good method yet. But given my primary use-case (listening, audio-only), the fact that in the case of video and audio you really can only watch/listen to a single performance at a time, and the fact that in general what's most useful for me is to have a queue of content that I'm going to watch/listen to, in sequence, non-browser tools turn out to be far more useful than browser-based ones.
Most especially when you throw auto-play and advertising into the mix, and find yourself with multiple auto-playing tabs amongst ... well, I'm embarassed to say just how many browser tabs I typically have open, but it's a lot.
Yep - tried going to a hybrid solution but the thing is 80% of my utilization of a browser is working on my startup, with the additional 20% being "general surfing" (ie: reddit, HN, blogs etc.)
If my split was different I'd feel quite different about it... I just need Hangouts, Mapbox, YouTube, etc to work 100% of the time without headache. Also running two browsers was difficult because it's like "where's that darn tab!!!" half the time ha.
My solution to this crap is to eventually do something like a pihole setup upstream from the browser and call it a day.