6. You can stop working, and live on the mimimum amount you get off other peoples taxes.
7. You can move to a country with lower taxes.
If all these freedoms seem to much work to you, the only person enslaving you is you.
I believe the the observation, about slave morality is being misunderstood.
But more importantly, the crux of my argument is this - if people are truly happy about the level of taxation, then why is it mandatory. For instance, you could have a minimal tax of 5% for core government functions and allow people to contribute any percentage they would above that to fund other various programs - you could even provide a guide. For current government functions to continue at their current level, the suggested donation for individuals at your income level is 55%.
If you don't accept that deal, then it doesn't seem that you are being honest with yourself that you have no problems with the level taxation.