Lowering income tax in America (Central and North)

[Tax Cow]

... so this kind of schemes of lowering taxes is only for rich people, isn't?

In a broader picture, yes. For low-earners, the primary legal tools are: Residency Change; Commuting from a nearby country; Temporary assignments abroad (i.e. A1 certificates in the EU every 2 years);

And illegal but still popular: Flying under the radar. This may involve asset/beneficial ownership non-disclosure; CRS evasion; photo-shopped documents; fake IDs; etc.