My point is that she isn’t some posh princess when we meet her in ANH.
And that is where we disagree.
No that’s where you are just plain wrong. She is a Senator who is captured in an act of espionage and is a leader in military resistance to the Empire. She can resist Vader’s powers and standard Imperial interrogation techniques and is really handy with a gun. So not just some posh Princess. She isn’t even that posh when she is talking to Han and Luke.