For me. Just because something is run in production doesn’t mean it is production ready. There are trade-offs you need to consider adopting something early on.
You should be prepared that there will be bugs and when those bugs are fixed the new version likely comes with breaking changes to the API, meaning more work to get running. You may also have to prepare yourself that the project goes nowhere and is abandoned (not saying this is likely to happen with liveview, just more a general reflection) and you have to either take up stewardship yourself or change technology.
Production ready for me means good documentation, stable APIs, some sort of guarantee of longevity (which sort of ties into the stable APIs) and clear upgrade paths from earlier versions.
LiveView can be run in production but in my opinion is not production ready yet
