Without its Fiat value Bitcoin won't be accepted by any vendors online or offline.
Says who? There is a merchant I buy from fairly regularly whom I (and several others) pay in bitcoin, who has told (and shown) me that he then uses that bitcoin to pay part of the salary of some of this staff members, and also to pay one of his suppliers. His employees which are paid partly in bitcoin are paid with a fixed amount of bitcoin, regardless of its fiat price. They earned relatively more in terms of fiat last June/July when the price was $13k, and they will earn relatively less currently in terms of fiat, but they always earned the same amount of bitcoin.
Bitcoin can function just fine without fiat. I earn a fixed amount of bitcoin from my signature and avatar, regardless of fiat price. I buy things from this merchant who pays his employees in a fixed amount of bitcoin, regardless of fiat price. There is no inherent need to convert to, or even think about, fiat when using bitcoin, unless you want to.