Giving an alias to function argument (now can make the query to fail)

The query, calling a UDF:

select Json_Object(5 as "five", 7 as "seven");

works fine; however, this one:

select greatest(5 as "five", 7 as "seven");

fails saying: "Incorrect parameters in the call to native function "greatest".

Indeed, in this case, aliases are useless but why flag this as an error? Perhaps a warning saying that these aliases are ignored would be acceptable.

BTW: The MariaDB documentation on aliases (in the tutorial) does not say anything about aliasing function arguments. This is an important feature for UDF's as it correspond to the attribute of arguments.