I am impressed. You pretty much nailed it, only once veering off into fantasy (free energy) and stuck to the point, which is existentially important. The most valuable wealth we can have is the high trust society we are part of. Very few understand that an ancient dragon guarding a hoard of gold in a deep, dark cavern is impoverished, has no wealth at all, because they are cut off from everyone that gives value to gold. It is society, dependent on their mutual love and affection for their ability to support one another, create, and share the blessings of civilization, that imbues everything valuable with value.
Billionaires in bunkers won't emerge to restart society and rule. Either society will become competent to sustain civilization, in which case billionaires will be nothing more than irrelevant when they emerge, utterly extraneous to every industrial network, or it won't, in which case billionaires will die clutching their precious, for which they sacrificed everything actually valuable.
The laws of physics mandate what tech can arise, and clever tinkers occasionally invent it. Since the Stone age centralization and economies of scale have been the forefront of tech advance, increasing productivity by making bigger investments, but that is over. You see on the battlefield that <$50k drones defeat >$B bombers, and last month <$100 manpads became available for little old ladies to print on their kitchen tables, like knitting doilies, and enable communities and even individuals to secure themselves from $50k drones and $B bombers alike. This happens first on the battlefield, where tech advances due to it's existential value in war, but this is happening in every field of industry today, from comms to transport, from food to fuel, and means of production of the goods and services that create the blessings of civilization increasingly shrink capital outlays and labor cost. Centralization is not civilization, but parasitizes it. Decentralization of production decentralizes wealth and power, and it is ongoing RN. This is why overlords are racking up unpayable debts in counterfeit fiat they are spending to acquire real goods they think will enable them to maintain their wealth and power during and after the ongoing collapse of the global monetary system that will render populations dependent on centralized production desperate, and enable them to starve us into submission - before we attain to sufficient wealth and power to ignore them until they go away.
It's too late. Enough of us are seizing the means of production suitable to our personal circumstances and creating communities that merit their wealth by making it that the hapless herds that don't and die won't prevent the meritocracy from succeeding. The laws of physics aren't legislated by corruptible chokepoints that can be bribed, blackmailed, or bullied, and as the economic crisis deepens the demonstration of resilience makers will provide will prompt everyone that can to join in and very rapidly the culture of dependence will disappear, leaving obligate parasites starved of hosts. Independence is freedom, and independent means is the best definition of wealth, and our posterity will inherit that prosperity they will merit by making it themselves in perpetuity.
The harder the crash - and it will be a hard crash - the stronger the incentive to be productive will be. Even if everything fails and humanity is reduced to scattered bands of hunter gatherers chipping rocks to survive briefly, that will not change the laws of physics, and the progression towards decentralization will simply begin again - as it has in the past. Whether I'm right or wrong about this time being the last time, the laws of physics that today mandate decentralization out competes centralization will not change, and mankind will eventually make the transition. Today reasonable folks have an opportunity to secure them and theirs from the threats of being starved into submission, slaughtered by drone armies, or GMO'd into a slave race, and mitigations and solutions to all the threats we face are available RN on every continent. I am confident that narcissistic psychopaths have not learned they are fallible, that society is the actual wealth and power of most value, and are winning their way into their graves with exceeding competence in droves.
The good people I have created good will in good faith with have my back, and I have theirs, and we will prosper and thrive or die trying. Since that's the best we can do, I am content with that goal and purpose in life. I hope everybody reading your post is also.
Thanks!