You're right that it has utility, but being fungible doesnt imply that it is automatically an investment.

Speculation is not the same as investment, and it is still completely non-productive.

Agree it doesn't generate wealth. It's explicitly a store of wealth.

Investment is a weird term because most people would consider keeping cash or cash equivalents (gold) to be investments, even if they don't generate wealth. Cash is also an opinion, in terms of the market.