Pretty sure one quick way to solve this is to be more precise with what one means by 'consume'. Thus we could say that we can't consume ethically in the economic sense under capitalism, but that it is possible to ethically source food, shelter etc. - even if it's very difficult.

The alternative is to read between the lines and see that if there is no way to ethically source the necessities of life under capitalism, then capitalism must be dismantled. Again, this seems difficult (to put it mildly). But to say that it's impossible is to beg the question against our online left-wing commentators to which you refer.

All that said, I think the idea of Revolutionary Consumer Unions is something that deserves serious thought and development. Take that idea, and the right sort of blockchain, and then something really cool might be possible.

Thanks for the interesting read - keep on philosophising!