He speaks that way about gold because he does not get a return on his investment like he does in operating companies.
However not all operating companies provide a return on their investment when they go belly up like the Delorean Motor Car Company did.
Buffett has historically invested in undervalued companies with a long history of profitability, positive return on investment, intrinsic value, and excellent management. Neither crypto nor gold meet these parameters. In addition, Buffett only invests in businesses that he understands (i.e., can explain to an eleven year old), which is why he had historically focused on razor blades, insurance, soft drinks, oil, and banking -- basic products that people use every day.