It's made to be used as a last resort. For instance if you need to grab another county that will open up the option to usurp or create a title and there are no other options available to do so (marriage, pressing courtiers claims etc).
It is purposefully expensive, unreliable, and costs you prestige (i.e. other characters look down upon it).
Why have a CB system in the first place if you just want free CBs on every county you want while only waiting a year (*cough OP cough*)?

















































