I don’t think this would be as good as you think, because we can’t “unknow” what we know today. The obvious one is giving up all the social progress we’ve made since then. Also, imagine knowing about climate change and being surrounded by people who either don’t know or are worried about it but don’t have the science we have today to understand the issue. All the nightmares we have today will still happen, but you’re trapped in the past knowing it all and not being able to do anything about it.