No court has found any of the mentioned software to be illegal so far, anywhere.
They are all interchangeable. Should one implementation be found problematic, in theory it can be swapped with another.
It's not comparable to DRM, where a particular software can be licensed for a particular digital protection mechanism. In this case either they all are, or none are.
You're still just focused on technical implementation and not the intent behind actions, which is also important and will likely be considered by the courts.
While there is no technical difference, there is quite a difference of intent between watching a streaming video and downloading it to circumvent copy-protection.
They are all interchangeable. Should one implementation be found problematic, in theory it can be swapped with another.
It's not comparable to DRM, where a particular software can be licensed for a particular digital protection mechanism. In this case either they all are, or none are.