That logic is similar to Thomas Malthus’ 1798 theory that agriculture could no longer keep up with exponential population growth, even though he failed to anticipate the role of technological innovation. In our case, just because our ecological overshoot is high, that doesn’t mean we can’t develop solutions (e.g., renewable energy and practices) to curtail it and sustain high incomes. So just because we use a lot of the Earth’s resources, that doesn’t mean we can’t moderate and legislate better to reach a healthy 1-to-1 balance. This way, high-income people don’t have to reduce their incomes.
Your assumption that high incomes associate with greater degradation of the Earth is another complication entirely.