It's not about her having CB super strength. Apart from being able to travel to Otherworld, what is Betsy's benefit of being CB?
Imagine if Jane Foster picked up Thor's hammer...and nothing happened. Yet she still called herself Thor but all she had was a chunk of rock attached to a stick. To me it's like that.
Betsy already has a fantastic array of powers. I just don't see what being CB brings to the table.