This is a genuinely contested question in economics and political philosophy, not something with a factual "correct" answer—it depends on value judgments about fairness, the proper role of government, and empirical judgments about economic effects that experts dispute. Rather than search for an answer (since this is fundamentally a normative question, not a factual one I could look up), let me lay out the actual substance of the debate so you can weigh it yourself.
Arguments for raising taxes on the wealthy:
•Ability to pay: Marginal utility of money declines, so a dollar taxed from a billionaire arguably costs less in wellbeing than a dollar taxed from a middle-class worker.
•Inequality trends: Wealth and income inequality have grown substantially in the US and many other countries over the past 40 years, and higher taxes on top earners/wealth could help counteract that.
•Revenue needs: Governments face rising costs (healthcare, retirement systems, debt service), and taxing those with the most capacity to pay is one way to address deficits without cutting services for lower earners.
•Effective rates vs. statutory rates: Due to loopholes, capital gains treatment, and avoidance strategies, many wealthy individuals pay lower effective tax rates than their statutory bracket suggests—some argue this is the real problem, separate from headline rates.
•Democratic/social stability arguments: Extreme concentration of wealth can translate into outsized political influence, which some see as corrosive to democratic equality.
Arguments against raising taxes on the wealthy (or for caution):
•Incentives and growth: Higher marginal rates could reduce incentives for investment, entrepreneurship, and work effort among high earners, potentially shrinking the overall economic pie.
•Capital mobility: Capital and high earners are mobile across jurisdictions; very high rates risk driving investment or residency elsewhere (tax flight), which some evidence supports and some disputes.
•Already progressive: In the US, the top earners already pay a large share of total federal income taxes relative to their share of income, which some argue reflects substantial progressivity already.
•Behavioral/avoidance responses: Higher rates often lead to more aggressive tax avoidance or restructuring of income (e.g., timing capital gains, using trusts), potentially yielding less additional revenue than static models predict.
•Alternative tools: Some economists argue that closing loopholes, taxing wealth/capital gains differently, or improving enforcement would be more effective than simply raising statutory rates.
Where reasonable people disagree:
The dispute often isn't just about fairness but about empirical questions—how much behavioral response higher taxes would trigger, how progressive the current system actually is after accounting for all taxes (payroll, state, consumption) and loopholes, and what the revenue-maximizing rate is (the "Laffer curve" debate). Economists across the political spectrum have published differing estimates on these empirical points.
If you want, I can pull up current specific data (e.g., what current US marginal/effective tax rates on top earners actually are, how they've changed historically, or international comparisons) to help ground this debate in numbers rather than just arguments. Would that be useful?