I have a hard time understanding the hang up on everyone paying federal income taxes for their entire adult life. All taxes need to be looked at together before you conclude that a significant share of people are not paying taxes. You also need to look over the lifetime of taxpayers.
I agree that paying taxes is a responsibility. It is a responsibility for all able people. I used to actually call it a privilege ... until it got to the point of being a ~50% marginal tax rate when almost all the rest of my income was going for student loans. Then it did feel like a burden, I'm not gonna lie.
I feel that for those whose earnings justify paying little or no income tax, some contribution of services should be expected. I saw the comments above about having to choose between volunteering and working for pay, but in my experience, people who work full-time (or more) tend to volunteer a fair amount of time as well. So I don't think it's ridiculous or punitive to expect part-time workers, unemployed people, and students to contribute services in lieu of paying taxes.
And then at minimum, you likely have to remove the very elderly, infirm, and disabled from any sort of volunteer requirement. And what about the student going to school full time and working full time? And then add in the cost and bureaucracy of administering such a program.I suppose we could institute some sort of token minimum federal income tax if it would make people feel better about everyone contributing for their entire adult life.
I know that when my husband went back to school for an advanced degree, and I was working full-time and homeschooling, we did not pay federal income taxes for four years. But we paid state, property, and payroll taxes. I would estimate between work and school, we were both easily putting in 80+ hour weeks, so I'm not sure where we would have fit in required volunteer hours. But now that we are paying state, federal, and payroll taxes at a significantly higher rate than before the career change and likely will for the rest of our lives, I think our four years of not paying will be way more than made up for.