Your concerns are not unfounded, but there is a very significant functional difference between being generally concerned about data privacy posed by any third-party bad actor, and having a threat profile that includes specific state actor threats.

If you think it is a realistic scenario that the US would serve a warrant against you, then yes, your iCloud backup will probably be disclosed to the authorities. But if this is a real concern of yours, then you probably have much bigger things to worry about than whether your SSD is soldered to the board or not.