Function Error Response Is Not Clear

To whom it may concern,

Some functions if they are missing the correct arguments give vague error
messages while others give specific ones.

Specific error message example query 1:
SELECT sum();
Specific error message example output 1:
ERROR: function sum() does not exist
LINE 1: SELECT sum();
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.

Specific error message example query 2:
SELECT sum();
Specific error message example output 2:
ERROR: function lower() does not exist
LINE 1: SELECT lower();
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.

Vague error message example query 1:
SELECT nullif();
Vague error message example output 1:
ERROR: syntax error at or near ")"
LINE 1: SELECT nullif();
^

Vague error message example query 2:
SELECT nullif(1);
Vague error message example output 2:
ERROR: syntax error at or near ")"
LINE 1: SELECT nullif(1);
^

Vague error message example query 1:
SELECT coalesce();
Vague error message example output 1:
ERROR: syntax error at or near ")"
LINE 1: SELECT coalesce();
^

These examples it is clear the function is the issue, but in my actual
query there were many parentheses nearby so I thought I had mismatched
parentheses for a while and it sent me hunting for the wrong thing wasting
precious time on a production bugfix mid-crisis. I do not know if any other
function besides NULLIF and COALESCE are affected by this. They are just
the two I happened to test.

Best,
Luke