This is a genuinely contested policy question where reasonable people disagree based on differing values and economic theories. Rather than search for "the answer" (there isn't a factual consensus one), let me lay out the actual debate so you can weigh it yourself.
The core arguments
Case for raising taxes on the wealthy:
•Fairness/ability to pay: Many argue that as income rises, the marginal utility of each additional dollar falls, so taxing high earners more causes less sacrifice than taxing low earners.
•Rising inequality: Wealth and income inequality in the U.S. has grown substantially since the 1980s, with top earners capturing a disproportionate share of income growth.
•Revenue needs: Higher taxes on the wealthy could fund public investments (infrastructure, healthcare, education) or reduce deficits.
•Effective tax rates: Some analyses show that very high earners, especially those with income from capital gains, can pay a lower effective rate than middle-class wage earners, due to lower capital gains rates and various deductions.
•Historical precedent: U.S. top marginal tax rates were much higher in past decades (over 90% in the 1950s–60s, though effective rates were lower due to deductions), suggesting room to raise rates without collapsing the economy.
Case against raising taxes on the wealthy:
•Economic growth concerns: Critics argue high taxes on top earners and investors reduce incentives to work, save, and invest, potentially slowing growth, productivity, and job creation.
•Capital mobility: Wealthy individuals and businesses can relocate income, assets, or residency to lower-tax jurisdictions, reducing actual revenue gains ("tax flight").
•Already progressive system: Some argue the current U.S. system is already highly progressive—top earners pay a large share of total federal income taxes relative to their share of income.
•Double taxation issues: Capital gains and dividends are often taxed after corporate profits were already taxed, so critics argue lower rates on investment income aren't necessarily unfair.
•Behavioral/avoidance effects: Very high rates can lead to more aggressive tax avoidance/evasion rather than proportionally more revenue (debates around the "Laffer curve").
Key empirical uncertainties
•How much revenue would actually be raised (estimates vary widely depending on assumed behavioral responses).
•How much economic growth would be affected (economists disagree, and the evidence is mixed depending on country, time period, and tax type).
•Whether to focus on income tax rates, capital gains rates, estate taxes, or wealth taxes—each has different effects and tradeoffs.
My take
I don't think there's a single objectively "correct" answer—it hinges on value judgments (how much you weight equality vs. growth vs. individual liberty) and empirical judgments (how responsive behavior is to tax changes) that are genuinely disputed among economists and the public.
If you want, I can dig into specific proposals (e.g., wealth taxes, raising capital gains rates, closing specific loopholes) or current data on effective tax rates by income group—happy to pull up current figures if that would help you form a view.