I'm guessing it's just a shoddy adaptation. If there's a source novel I'd assume it explains all of these things. A lot of stuff just felt under explored like we didn't even really get any insight into the relationship between the duke and his brother or family. The brother in general is just kind of there not doing anything. The FL's mother is on screen for like 2 panels. We know nothing about the Saintess's old life except that it sucked. So much under explored stuff

Nooooo lovers quarrel (/TДT)/
And wtf is the god doing there just like that
And how were they able to live for a thousand years, like the story is good but it's just missing a lot of things, and important world building stuff which makes the reader confused as to what's happening, still loved the concept,