Abraham is in that list, and is elsewhere described as the paragon of faith. Yet in Genesis 18/19 Abraham is said to have met and talked with God, and discussed the destruction of Sodom, which Abraham then witnessed immediately. Abraham's faith was not a belief in a God he had never seen.
Likewise Cain, Abel and Noah are in the Hebrews 11 list but Genesis says they spoke with God before they exercised their faith.
In Hebrews 11 the "things unseen" are elaborated as the creation of the universe and the future fulfillment of God's promises (almost entirely the latter). They're unseen not because there is no evidence for them, but simply because the faithful people did not live to see them fulfilled.
"Faith is belief without evidence" is a trope widely believed by Christians and atheists, but that's not the faith being promoted in Hebrews.