First of all, you're wrong about how debt is financed. It's not via inflation, it's by taxes. Interest payments accounted for 13% of the federal budget last year. That's enormous. (Yes inflation reduces the value of debt over time, but debt carries interest which generally outweighs expected inflation.)

Second, Congress absolutely adjusts tax rates as well. Not precisely one-to-one to match spending each year, but over the long term it's all got to add up. Every dollar the government spends today is paid with people's taxes either today or their taxes tomorrow.

Third, the person who received the tax credits isn't being affected "equally". If 1% of people get the credit, but 100% of people pay for it, then the people who receive the credit end up hugely ahead in the end, while the other 99% lose out. So yes, for the 1% of people getting an electric vehicle tax credit, it is almost entirely paid for by the other 99% of people.