I’m sorry, but Your claim is revisionist.
A young earth belief was the norm before modern evidence to the contrary:
“The chronology dating the creation to 4004 BC became the most accepted and popular, mainly because this specific date was printed in the King James Bible.[19] The youngest ever recorded date of creation within the historic Jewish or Christian traditions is 3616 BC, by Yom-Tov Lipmann Heller in the 17th century,[20] while the oldest proposed date was 6984 BC by Alfonso X of Castile.[21] However, some contemporary or more recent proponents of Young Earth Creationism have taken this figure back further by several thousands of years by proposing significant gaps in the genealogies in chapters 5 and 11 of the Book of Genesis. Harold Camping, for example, dated the creation to 11,013 BC, while Christian Charles Josias Bunsen in the 19th century dated the creation to 20,000 BC.[22]
Several early Jews also followed an allegorical interpretation of Genesis, including most notably Philo (On the Creation, III.13).[23]
The Protestant reformation hermeneutic inclined some of the Reformers, including John Calvin[24][25] and Martin Luther,[26] and later Protestants toward a literal reading of the Bible as translated, believing in an ordinary day, and maintaining this younger-Earth view.[27]
An Earth that was thousands of years old remained the dominant view during the Early Modern Period (1500–1800)”.
https://en.wikipedia.org/wiki/Young_Earth_creationism