No, it really wouldn't be. Take a look at any of the countries held up as "shining lights that we must immediately emulate" on the subject of universal healthcare. Can you find one with lower tax rates?
Even aside from that, there's one very important word that you don't seem to understand: VOLUNTARY. Right now, what I do and don't pay for my healthcare, and who I pay it to, is MY choice. I decide who to pay, how much to pay, and what to pay it for, and the only reason I lack as much choice and control on the subject as I currently do is because of government busybody interference. What you are suggesting is that I should surrender all of my control and my choice on this subject to the government in the hopes that - for the first time in the history of humanity - government will somehow manage to be more cost-efficient than the private sector.
I have seen what the government provides in the way of healthcare when they're put in charge. I'm not interested in trading out my current healthcare for that, and I'm definitely not interested in funding the the massive, wasteful, bureaucratic nightmare that is government control of anything.