Ask HN: How to incentivize people for a long term project?

Hey HN, I’ve been thinking about building something that will likely require 2-3 centuries of work and long term commitment with not so shiny day-to-day progress, at least in the first 20 years. How do you incentivize people for such a long term thing. Especially normal everyday people, who are busy making their ends meet. One way is to connect their support with some kind of real world wealth/prestige/capital.