Currently, 10–15% of GDP per year flows into corporate retained earnings never to leave. Think about the long term ramifications of that for you and your purchasing power.

That part is just an artifact of the tax system. The aim of corporations is to return excess earning to share holders. But because dividends are taxed, corporation essentially return their earnings as high share prices.

If it weren't for this, many more corporations would be hit by corporate raiders eager to unlock those retained earnings.

But overall, yeah, there has a flood of profits that have piled up.