What are the unintended consequences of that? If a capital gain gets taxed at 35%, it follows that you will have less incentive to seek capital gains in higher risk investments. Look at the paucity of VC and angel investing in France for example — extremely high capital gains taxes result in much more conservative investing and thus a relative lack of funding for startups. Much startup investment is from quasi-government programs that require Byzantine and Kafka-esque processes that favor “safer” businesses that fit in with central planned priorities rather than businesses that might become truly disruptive.

It’s simplistic to suggest making tax rates the same. Capital gains are what drive investment. Increase the tax on investment and naturally, you will get less investment. Capital gains are a reward for risking capital. You lower the reward, you will create a reduction in investment — which has a much more deleterious economic effect than the marginal gain achieved from raising the tax.