It's the externalities of the consumption - the waste left for everyone else to deal with that should be taxed. That tax should occur where the decision to create the waste is made. The responsibility should be on the producer of the product, not at the point of sale.

Additionally, the accumulation of capital should be taxed since it creates leverage that is used to easily make more capital passively (that is redistribution of wealth, which if you are for that then just say so instead of concocting arguments to achieve this ulterior motive). Capital gains tax is one way of approaching that. Even after this increase, the tax is still lower than most peoples working income tax.

I have no issue with a capital gains tax. Nor do most people. The bigger issue is with just taxing capital.

Also, this focus on capital is too narrow. It hides other forms of power that have captured our system: military, legal, media, etc... These forms of power obscure their power by redirecting attention to just capital.

Lastly, if you are concerned with external effects then tax the external effects directly instead of an indirect thing. So tax pollution rather than production in general.