As someone from a poor family, never received inheritance of any kind, and now (40 years old) makes +/- $1M per year, I climbed through every 'tax bracket'. The income tax system is absolutely designed to make it very hard to move through working class into middle class, and then from middle class to upper middle class.
Once you have escape velocity, you've got room to move with debt facilities and other options. Everyone wants to give you free, high quality banking services. It gets easier. But moving from, say $70K to $500K is very very hard specifically because of taxes.
For a very long time, the cumulative sum of taxes I'd paid were more than the money I actually had in my account, to invest and pay for things.
Ted Cruz was right, taxes should fit on a postcard for everyone.
And no, unrealized investments shouldn't be taxed and no one except do-nothing journalists are surprised to learn that they aren't - this ProPublica article is really the definition of fake news.
Actually let me just say what it is: propaganda leaked in order to build support for the president's tax increases, which are a very bad idea.