I want to address the 'just invest in your career' advice that gets thrown at young people, because it's right but incomplete.

Yes, increasing your income is the highest-leverage thing most people can do in their 20s and 30s. An extra $10k in annual income, invested over 30 years, is worth significantly more than any optimization to your expense ratios.

But 'invest in your career' is not a complete financial strategy. It doesn't tell you what to do with the income once you have it. And the evidence is clear that lifestyle inflation reliably absorbs income increases unless you have a system to capture them.

The full picture: grow your income aggressively, and simultaneously automate savings so that a predetermined percentage of every raise is captured before lifestyle adjusts. These two strategies compound each other. Either alone is good; both together is how wealth is actually built.