They didn’t drop them because of money costs, where did you get such a statement?

In any event they didn’t really have much of a choice, even if they dropped the ball by not simply resurfacing the old SMS product they did and do have. Having SMS and have people assume it was private because it was on Signal had already caused various issues, of the kind that causes bad mouth-to-mouth for your service. Signal’s response, while adequate, was also lazy.