Miners age like fish. Not fine wine. The moment they come off the assembly line, their value is decaying rapidly. With hashrate going up forever (Laura), miners might have a shelf life of ~3 years (making this # up). If the cost and maintenance of the miner does not recover enough sats to cover itself, then even with free electricity it will be unprofitable.

It is a well-understood business tactic to operate at a loss long enough to force your competition out of business.