You're omitting the base rate. The base rate probability for an arbitrary drug to treat a disease with no treatments is probably extremely low, < 1%. There are

You're omitting the base rate. The base rate probability for an arbitrary drug to treat a disease with no treatments is probably extremely low, < 1%. There are thousands of drugs; at most a few treat COVID-19. Suggesting that any single drug has a significant chance of a positive effect puts it well ahead of the pack. By contrast, the base rate for a former Senator doing an okay job with the Presidency is probably in the range 20-80%. Suggesting that Biden would do as well as any other former Senator (may or may not) is not an endorsement, but suggesting he would do much better than the base rate is definitely an endorsement.