And a lot of cultures celebrate like the 100th day of life with some ceremony because so many babies died before that in antiquity. Humanizing babies, and I mean actual babies, is also modern. Heck, until recently people could be treated as property so even humanizing humans was a recent turn of events.
Shall we judge things by antiquity standards, is that really smart?
Anti-abortion advocacy is rather new, and old-timey at the same time. The arguments more or less haven't changed since the 50s. For the majority of the time since Roe nobody really cared - the American right shifted to other divisive politics. In the past 10 years they shifted back. Not sure why, maybe they felt as a party it was a strategic entry point into the topic of 14th amendment privacy as a whole. Certainly, that seems plausible when individuals such as Justice Thomas have alluded to taking aim at other protections of that nature such as Loving and Obergefell.