What extra information does a Bond Line View provide compared to a Fisher projection?
A bond-line view shows NO stereochemical information.
It shows only the connectivity of the atoms, that is, which atoms are connected to which.
For example, here is the bond-line view of glucose.
It could represent the structure of any of the 16 isomeric aldohexoses.
In contrast, here is the Fischer structure of D-glucose.
If you remember that the horizontal bonds represent wedges, the Fischer projection gives the absolute stereochemistry of every chiral centre in the molecule.
There is only one molecule, D-glucose, that can have this particular Fischer structure.
A Fischer structure gives much more information than a bond-line view.