Maybe it’s just me, but the idea of starting a company that exists 1,000 years into the future is much more exciting than building a startup in a trendy industry, getting acquired for big bucks, and never being heard of again.
Most entertainment business are also not solving problems, and yet manage to be extremely successful businesses. See: Disney, Pokémon, video game companies, etc.
Is food a problem? Clothes? Housing? Historically societies that have lacked markets in these (grow your own food, make your own clothes etc) are not something I would call as aspirational models for our current civilization.
I seize the opportunity to wish you a great satisfying and fulfilling life in harmony with the rest of your relatives, whoever you are.
Their structure seems to have been like a private corporation, with special rules and efforts to maintain their ideology and culture. They had the ability to expand outside the current leading families when necessary, though.
When they hit the recent hard patch, they pivoted, but didn’t scale back enough to survive until the next great leader showed up. They fell into the hands of modern corporations, and we all know how that turns out.
One answer would be focusing on basic human activities. People will still probably be eating and traveling in 500 years.
Another would be to figure out and/or develop the “temple” of whatever future belief system or religion one thinks will be necessary and popular in the future. And this could be a currently existing religion; Islam and Christianity will probably be around in some form or another for a long long time.
With wooden furniture you are (at least for some time) also blocking release of stored CO2 back into atmosphere, a fate all other wood faces.
1. Datacenters or datacenter construction may be the most high-tech ones I would try. Not cloud services, but the literal physical buildings.
2. Musical instruments, art supplies, or other cultural/religious goods of some kind, possibly as high-tech as electric guitars or synthesizers (although those have not historically gone well).
3. Financialization businesses like insurance or securities packaging of some kind could work (if you don't get high on your own supply).
4. Food and hospitality never go out of style.
I assume that the way this sort of business would work is a 3-step process:
1. Start by becoming the best in the world at something very weird and specific.
2. Bootstrap your business with enough connections to start making sales without needing significant financing. Run as a completely bootstrapped business.
3. Convince your children to continue being the best in the world at that thing and maintain your values. If you don't have any suitable children, adopt one. Also, make sure to disinherit any children who are not both very competent and fully onboard with the plan - you need to keep the power concentrated in the one or two best successors.
It's no accident that a lot of these long-lived businesses in Japan, where all three of these are part of the culture.