Time and again, nations, cultures, empires, and religions have crumbled in the face of change, not because they weren't true to their roots, but because they failed to adapt. Near the "fall" of every major empire there is a massive internal movement of fundamentalism. Searching for answers in the past, these purists cling to ideas, teachings, and traditions with more fervent zeal than even creators of those very ideas, teachings, and traditions ever held. Almost always, they miss the true point. Greco-Roman classicists claim that all understanding must be rooted in classical teachings, forgetting that those teaching focused on exploring the world by not being limited to ideas from the past. Neo-Confucianists focus on the social structures that Confucius said were lacking, but miss the reasoning and responsibilities behind those those relationships. Fundamentalist Christians focus on Mosaic Law, entirely forgetting Jesus' New Covenant. Almost always, this sort of backwards thinking leads to the collapse of the very thing that they were trying to reform.
For me, history is a fascinating tapestry of the myriad attempts that humans have made to make the world (or at least their piece of it) better (at least for themselves). It is an interweaving epic of successes and failures, and all of them by flesh and blood people just like you and me. There are certainly many things that we can learn from the past, perhaps even great ideas that had long been forgotten, but it is in building off of them, rather than creating cheap copies of them, that we grow as a human society.
For example, when people talk about "making America great again," they are often fondly thinking of the "good ol' days" of the late 40s through early 60s when the U.S. economy seemed to be unstoppable. I usually jokingly remind them that if they truly want to go back to those times, they need to return the top tax bracket to 90%. I say "jokingly" not because it isn't true (it is; look it up), but because that sort of tax structure is unsustainable--that's why it ended (and what has followed is also unsustainable). Something different, something better, needs to be built.
I find it ironic that most people who want to return to "simpler times" do not have an understanding of just how complicated things used to be (or even are). They want to return to a time that only exists in their imagination. I'm of the belief that, as long as we are using our imaginations anyway, let's use those imaginations to build a better and brighter future.