Great to point that out.
I think Humanism role is to refine and defend this idea that the highest, most fundamental principle is human welfare, which is a large term to refer to a spectrum:
self-preservation (access to life) → welfare (access to health and psychological/intellectual autonomy) → individual development/fulfillment (hedonism and individualism)
Individualism is just a refinement of psychological/intellectual autonomy.
Hedonism is just a refinement of access to health.
Autonomy and access to health are just refinements of self-preservation.
At each state, science and Reason play a major role:
_You can not have self-preservation, access to health, and hedonism without science.
_You can not have self-preservation, psychological/intellectual autonomy and individualism without Reason.
(Therefore the topic on romanticism → What do humanists think of romanticism?)