Everyone and anyone knows Bitcoin follows the longest chain, but also the chain with the most proof of work.
Welcome to 2010 (when Satoshi changed from longest chain wins to longest chain + most PoW wins).
You're playing irrelevant semantic definition of terms diversion. The longest-chain is the one with the most PoW in which the length is correctly calculated by cumulative difficulty.
Just because the longest-chain was incorrectly measured in the past doesn't mean that the longest-chain means today anything other than the "longest cumulative difficulty in a chain of blocks which are linked by cryptographic hashes". Do you really expect someone to write that quoted text instead of the short-hand "longest-chain".
Everything you're saying is a diversion anyway
Longest chain, most PoW, does not matter once the 2 chains are separate, they're separate coins at that point. And that is the point.
So, saying miners are compelled to follow the longest chain is meaningless. By that logic, there would be no altcoins in existence, as they would all have to observe the chain with the most PoW. Which is demonstratively untrue, to wit: a thousand altcoins.
You made 2 false claims. I've demonstrated them false.
Apologise.