Godolkin finds out about the virus and adjusts it to kill off large number of weaker supes and possibly humans in a single hit; he can hardly force each supe individually to commit suicide, he would be there for another ten seasons. As he is a gifted scientist it would not be beyond his characters boundaries for him to be able to rework the virus significantly. This would setup a brand new antagonist to keep the virus in play, Homelander is hardly smart enough to do it himself.