If the columns are you select is fixed, then execute immediate will be fine, eg

l_sql := 'select c1,c2,c3 from mytable where 1=1 ';

l_sql := 
  l_sql || 
    case 
      when bind1 is not null then 
        ' and mycol = :bind1 '
      else 
        ' and :bind1 is null'
    end;
    
l_sql := 
  l_sql || 
    case 
      when bind2 is not null then 
        ' and mycol2 = :bind2 '
      else 
        ' and :bind2 is null'
    end;
...
...

That way, the number of binds is fixed , so you just do

execute immediate l_sql using bind1,bind2,bind3,.....bind10;

even if some of the binds are null.

If you want more flexibility, ie, the columns you select is variable etc, then its time for DBMS_SQL

https://asktom.oracle.com/pls/apex/asktom.search?tag=execute-immediate-dont-know-how-many-input-variables