I don't mind externality taxes. I don't like sin taxes. If you need free money to treat smokers and their lung cancer, taxing cigarettes is fine. If your goal is to stop people from smoking, I don't like it. It's paternalistic.
The idea that 'most taxes are paid by the rich' is a trick of math and that's it. The working poor have already been taxed through the function of having their consumption reduced. I hope the next two paragraphs capture the idea.
Consider this, if I buy a plowhorse for my farm, the total taxes I pay goes up because my total income has gone up. If the horse gets better at its job, my taxes go up even more. If I figure out how to cut its feed efficiently, or if I figure out how to cut its living conditions efficiently, my taxes go up (because its feed is deductible). This is because I capture the majority of the horse's productivity as profit and then I am taxed on that profit. Some people would then say "oh, the horse is not contributing very much to society! It pays zero taxes!". But, it's very clear that the horse is a net contributor to the economy as a whole. But if I can cut its wage by reducing its heat or by feeding it less-tasty food, then my taxes go up.
It works the same with my technicians. I bill them out at $100 per hour. I pay them $20 per hour. Marginal costs are $30 per hour. So I make $50 per hour off of their labour. They get taxed on the $20. I get taxed on the $50. If I can reduce their pay to $15, I get taxed on the $55 and it looks like my total tax contribution has gone up and theirs has gone down. Their contribution to society hasn't gone down. If they get better at their job, so that I bill $120 then I get taxed on the $70 and they continue to get taxed on their income. You'll note that in the $120 scenario, it doesn't matter who caused their value-increase. I could have bought a new tool. They could have bought a new tool. Whatevs.
Your entire life, productivity has compounded. But labour's share of the productivity capture hasn't risen. There are two theories for why this has happened. First, the worker has contributed zero to the increase in productivity and all of the productivity gain has been because management is superior. OR productivity gains have been from arenas where it did not increase labour's negotiation power. I believe it's the second.