The government already owns the fruits of a percentage of your labor. And a percentage of your income from assets.
That's also wrong when the percentage is too high (and it's too high in almost all countries). Doesn't change what parent comment said.
I'm not seeing much of a conceptual difference between owning a portion of your life by having a monopoly on all of your time for a limited period vs. owning a portion of your life by owning a percentage of your working hours in perpetuity.