Whether you think reserve currency status benefits a country (e.g., USA) depends primarily on whether you focus on consumption vs production, as well as the short-term vs long-term. The supposed benefits of reserve currency status either come with real trade-offs or are misattributed to reserve currency status.
The benefits of reserve currency status are mainly short-term: being able to run persistent current account deficits by issuing liabilities denominated in the reserve currency (e.g., dollars). This gives other nations a claim to real goods or assets in the future. Capital inflows benefit the financial sector by increasing asset prices, but come at the cost of productive investment in tradable sectors and industrial capacity. Demand for dollars leads to an appreciation of the dollar’s value relative to other currencies. This benefits importers at the cost of exporters.
The claim that reserve currency status leads to lower borrowing costs conflates correlation with causation. While demand for the reserve currency marginally reduces sovereign interest rates, this effect is usually overstated. The argument is also not supported empirically: the U.S. has had higher interest rates than many non-reserve currency countries such as Switzerland, Germany, and Japan. But even if you accepted this argument, there are other tools to control borrowing costs. Central banks in countries with floating exchange rates have control of interest rates. Theoretically, they could engage in direct money printing to fund their spending. This would avoid the issuance of debt instruments entirely. Even under current legal constraints, central banks have plenty of tools–such as yield curve control (YCC)–to control both short- and long-term interest rates.
The main benefit of reserve currency status is the control and leverage it provides in global finance. For example, it gives the U.S. power to impose extraterritorial sanctions and conduct global financial surveillance. However, over-reliance and weaponization of these tools undermines the stability and neutrality required of a reserve currency and gives an incentive for other countries to circumvent these restrictions (e.g., by developing alternative payment system) and reduce their reliance on the reserve currency (e.g., to de-dedollarize) over time. Sanctions have had mixed efficacy and often impose costs on parties that were not the intended target. A shift to a more restrained foreign policy would reduce the foreign policy establishment’s need for these tools.