Feels like if BTC is a commodity, then BCH and LTC clearly are as well, no?
Gensler has commented on those specifically in the past [1].
They aren't. Bitcoin's blockchain has a longer proof-of-work than BCH. Honest nodes will only mine the longest blockchain (per Satoshi). Therefore any blockchain shorter than Bitcoin's will ultimately collapse in the long term, making them unsuitable to be considered commodities.
Water and oil are both fungible commodities. No one would claim they're economically interchangeable with each other.
Every point you make doesn't seem to make much sense.
Perhaps try some online learning resources: https://ocw.mit.edu/courses/15-s12-blockchain-and-money-fall...