The title proves ownership (kinda), but does not define the outline of the property itself.

If the you need to know if the fence is on your property or the neighbor’s, a title or deed won’t help you find that line.

So if the official survey is lost and you need to know where the land you own is, you will need a survey.

Recorded deed will more or less universally contain a legal description of the land. This does, in fact, defined the illegal outline of the parcel.

A survey is little more than marching out into the field and putting at the location where you believe the boundaries to be based on your review of the legal description.

Of course that’s not the end of the discussion as to boundaries for reasons like adverse possession or busted titles but on his own a surveyor is going to tell you basically nothing.