Traditionally (before the 90s) stock index growth was driven by retirement investment, which is driven by demographics (more workers or richer workers). Recently, most dollars added to public exchanges come from corporate buybacks (companies seeking to go private).

The only disadvantage to private investment is liquidity. Otherwise, it's way better to be non-public (less hostile takeovers, less activist investors, less regulations, less mandatory transparency, less managing for 1Q instead of 5Y).

This feels like more evidence for a tipping point between capital and labor.