Oracle: Apply an expression on all columns of a table

with params as (
   select '% is null' as expr,
          'or'        as joiner from dual   
)
select
   listagg(regexp_replace(params.expr, '%', c.column_name),
           ' ' || params.joiner || chr(10)
   )
from
   params            cross join
   dba_tab_columns c
where
   owner      = 'SYS'        and
   table_name = 'DBA_USERS'
group by
   params.joiner  -- prevent potential ORA-30496: Argument should be a constant.
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