Yeah, I’m not really arguing for or against the word fish technically fitting all land animals. I think that using it that way showcases the problem of trying to fit common terminology like “fish” into the scientific taxonomic system. The definition of fish has no use in that context.
Also, there are fish which are also arguably tetrapods https://en.m.wikipedia.org/wiki/Sarcopterygii
Yeah, this is the distinction I’m trying to draw between “common” and “scientific” terminology. Scientific taxonomy is based on evolutionary history, rather than just superficial traits like “has gills, fins, and lives mostly in water.”