Why separate operator/system instructions from end-user messages?

Question

Accepted Answer

Operator instructions define product policy and should not be overwriteable by untrusted users — System/operator text is the product policy layer; users shouldn't be able to casually veto it.

Answer

There is no difference; both are identical in trust

Answer

User messages are always more trusted than system

Answer

System instructions only set font size

Why separate operator/system instructions from end-user messages?

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