> Approximately 6 in 10 households in the United States own securities investments—typically through taxable accounts, IRAs or employer-sponsored retirement plans. However, this figure drops to a little over 3 in 10 if only taxable investments are considered. Households that own taxable accounts are more likely to be older, affluent, college educated and white relative to households with only retirement accounts or households without investment accounts.

* PDF: https://www.sec.gov/spotlight/fixed-income-advisory-committe...

The 3-in-10 would also have sheltered accounts:

> Importantly, most of these taxable investor households (89 percent) also own a retirement account like a 401(k) or IRA.

I stand by my statement: most people don't have to worry about tax events in mutual funds, and those that are in the situation have a 'good problem'.