We would have, had the Roman Empire never fallen, the Dark Ages intervened and a few plagues interspersed here and there.
Knowledge was accelerating at a logarithmic pace, as it always does. The principles of basic mechanics, steam and jet engines were already known.
Just look at the 20th Century. Life at the beginning was not a lot different than Roman times, horse and buggy technology with a steam engine and rudimentary electricity and telephones. In less than a half century, one lifetime, we went from that to exploding a hydrogen bomb and guided missiles.
Imagine if that level of technology were available to the barbarian despot kings of the Franks, Germans, Pics or Celts?
The fire at the Library of Alexandria, and others of its like, wasn’t an accident............
IOW, the muzzie destruction of the ancient world — which includes the incineration of the Library of Alexandria and the fall of Constantinople — saved us all from nuclear annihilation.
Poppycock.