Why does my skin still feel dry after hyaluronic acid?

Hyaluronic acid helps attract and hold water, but a serum alone may not provide enough protection against water loss. I would especially check whether the moisturizer on top is adequate and whether another step in the routine is increasing water loss or irritation.

Hyaluronic acid cannot fix the whole routine

Try pairing a tolerated serum with a suitable moisturizer rather than repeatedly adding more serum. Also review cleansing, exfoliation, and indoor dryness. Persistent tightness does not prove that hyaluronic acid is stealing water from your skin.