Oh, Please, John’s contribution was interesting and informative about need for cutting in entanglement, who cares what type? If someone tosses a lacy thong overboard and it snags on coral and your fin, aren’t you going to want to be ready with EXACTLY the correct cutting tool for the situation, regardless of whether you had prepared for that specific eventuality? Please let’s keep an open mind.
I dont think you read anything I wrote. Freeing a fouled prop is not "entanglement" in the sense of a dive accident.
But yes, I agree that a knife can be a useful tool for some tasks. As can many other things that divers bring with them - sledge hammers, pry bars, dredges, spears, etc..
Bring what you like.