Not where it contradicts another constitutional provision. One or the other must be invalidated. Since income tax is essentially devoting a portion of the fruits of your labor to the government, it is involuntary servitude, which contradicts the (earlier) Thirteenth Amendment prohibition.
So the Court has had to resort to Robertian “logic” to affirm that involuntary servitude is not involuntary servitude, and that a tax on income is therefore legally sustainable. In that sense, you’re right, but only if you accept the principle that “’constitutional’ is whatever the Supreme Court says it is.”
By that logic, all taxes could be considered involuntary servitude, since all money could be construed as as the fruits of labor.