The cost of legendary scrolls is way too high 17usd and then 43usd (week) just to scroll 1 legendary to max it is insanely high.
Lots of players abstain buying champions they can afford obtaining just for the pure fact that legendary scrolls costs too much.
The difference in between unscrolled legendary and fully scrolled epic it is like 10-20% depending on the use case.
Probably there will be way more spending in pulls if people would be able to afford the skills too but since they see the massive difference in between scrolled and unscrolled leggos they might be : ok i can skip this banner and focus on the banner i'm currently building a team for...
Adding more legendary scrolls as quests rewards/event rewards or maybe in-game drops like farm X dungeons / week to get 1 scroll would be benefical as revenue point of view and for community too