This analysis misses altcoin mining. When mining adjusts on BTC, miners don't just turn off their rigs. They can go mine altcoins. This behavior introduces another dimension to mining economics. Miners are practical. They have to make money with their hardware and electricity. They can't afford to be ideological.
In the Bitcoin mining world (SHA256), miners like to have BCH, BSV and other alternatives. Altcoins allows them to diversify. That's why these chains will never die. They always have mining support.
They'll die if they can't make enough returns to pay for the electricity (and I'd be happy if we helped make that a reality through a tax on carbon and/or POW mining itself).
In the Bitcoin mining world (SHA256), miners like to have BCH, BSV and other alternatives. Altcoins allows them to diversify. That's why these chains will never die. They always have mining support.