Don't get me wrong, everything about this model sucks -- it's just not as straight forward as it might seem.
And by being unethical and double dipping you're setting a great example for your customers who won't feel bad about being unethical themselves and just blocking and bypassing all your monetisation. If a site is being honest and fair I'm also much more motivated to play fair with them. I used to with Amazon and Netflix and paid my subscription until they started charging extra to remove ads. Now I pirate again.
Ps by 'you' I mean the companies that choose to do this, not you the poster.
I don’t disagree with the message wholesale, but blocking ads is not unethical. It’s a vital defense mechanism against outright malicious actors or the excesses of the attention economy. There is no opt-out or alternative, and there is no consent.