Because, as an actor, she hasn’t done as much to improve her brand, compared to Duchovny.
Studio bean counters use a stupid formula that they won’t budge from – instead, they should have basically offered her whatever Duchovny is worth, because HER CHARACTER is worth that much.
That would make sense. Don’t apply sense.
When The X-Files first premiered in the ’90s, Gillian Anderson was paid far less than her male co-star. But how did that almost happen again for the revival?