PoS reducing sell pressure - mining costs vs tax

I read in an interview Andrew Keys said

"Two imminent catalysts to increasing the value of Ethereum include EIP 1559, wherein ether is burnt for every computational and storage transaction; and Transition to PoS, which reduces “sell pressure” associated with proof-of-work mining costs like electricity, hardware and real estate. Most miners have to sell 75% of what they mine to pay these monthly expenses."

Won't the sell pressure come from having to sell the earned ether to cover potential tax, as in many countries rewards will be seen as income/distributions.

Let's say I run 3 nodes and receive 7 eth/year - if this is received when eth price is at $4000 and I get my tax bill when eth price is $1000 I'll end up paying tax on $28000 income - so the tax alone would be greater than the now $7000 I have available to cover it (so I'd have to sell as soon as receiving the ether to ensure this doesn't happen).

Follow-up question - will it be possible post-merge to withdraw earned eth at point of earning it?