Lol, classic hand-wavey "Just be rich" nonsense.

People don't invest the bloody stock market because they can't afford rent and groceries.

If labor's share of GDP were more equitable, and more akin to what it was during the US's "Golden age" then sure, us regular folks might have some money to invest, but since the rich are gobbling up literally everything these days, a lot of us out here are struggling just to get by, and don't have money to pay our bills let alone invest.