Earlier quoted context omitted.
It should be the place of Government to ensure that these externalities are re-addressed (e.g. by taxing companies on every item of theirs which goes into landfill), and for us the citizens to lobby them to do so. That won't eliminate the externality. All appliances will now cost $X more. In the meantime, the government will have collected $X*N more revenue, but it won't have gone toward recycling the decommissioned…
It would make a difference - an appliance that would last 15 years would be $X more expensive, but buying 5 appliances that each last 3 years would cost 5*$X. If $X is meaningfully large, it becomes a strong motivation to prefer things that last longer.
But I feel confident in predicting that it won't address the other side of the coin, that revenue would be used to actually keep the old appliances out of landfills, and to recycle their components. I'm hard pressed to think of examples of putatively earmarked taxes where the entirety of the revenue still goes to what it was originally promised for.