This is my take.
You got a source for this? (Genuinely asking, I have no idea about any of the details of this story).
My understanding is that her father ceded financial control to a court-appointed conservator, so I’m skeptical of the financial angle. I have no clue what sort of person her father is. The reason I’m a little skeptical of the dominant media narrative - that is, that this is outrageous and Britney is being held prisoner - is that it’s totally impossible for the conservators to defend their case publicly. They can’t very well be like “well here is a list of 50 batshit crazy things she did which is the reason this is happening”, so I’m hesitant to rush to judgement.