there are two facets to "is rationalism good".

one is, "is there a rational description of the universe, the world, humanity, etc.". Some people think there isn't, but I would like to think that the universe does conform to some rational system.

the other, and important one is, "do humans have the capability to acquire and fully model this rational system in their own minds" and I don't think that's a given. the human brain is just an artifact of an evolutionary system that only implies that its owners can survive and persist on the earth as it happens to exist in the current 50K year period it occurs in. It's not clear that humans have even slight ability to be perfectly rational analytic engines, as opposed to unique animals responding to desires and fears. this is why it's so silly when "rationalists" try to appear as so above all the other lowly humans, as though escaping human nature is even an option.

Uh-huh. Rationality is open-ended, we're apparently not very good at it and room for improvement is plentiful. However, I can still try to be rational, and approve of rationality.