If a person makes $1 million from wages then they are paying in excess of 25% federal income tax. If someone is earning $1 million from tax exempt interest, capital gains, and/or dividends then I agree they won't likely be paying 25% federal income tax.
We can dig a bit deeper looking at some hard data. In 2016, the latest year we have data available at the moment, there were 192,849 returns filed with AGI between $1m and $1.5m. Now, AGI doesn't necessarily equate to economic income but let's set that aside for the moment. Those taxpayers reported aggregate AGI of $232.6 billion. Those taxpayer reported tax liability after credits of $63.7 billion. That equates to an effective tax rate of 27.4%. Now, back to the question of AGI versus economic income. We can look at the detailed data and compute these taxpayers economic income. Those taxpayers reported total income of $237 billion. The difference between the AGI and total income was $3 billion in tax-exempt interest, $0.2b in exempt social security benefits, $0.2b in foreign-earned income exclusions, and deductions for things like self-employment tax, retirement contributions and alimony payments. So if we take that $63.7 billion amount and dividend by their total income of $237 billion then we get 26.9%.
Now we can run this analysis all the way up the AGI scale but what the cold hard data shows is people with incomes of $1m to $1.5m pay >25% in federal tax on their income. Of course, that doesn't include state and local taxes they pay also.