Could it be you were implying that, the table has already been imported before the transformation could be applied, so it's incorrect already?

The table was loaded into the power query but not the power bi desktop. As a data analyst it is important to always consider efficiency and performance. It does load the entire table first and not just a sample, while a filter transformation would limit the data before loading into the desktop the processing time to apply the transformation across the millions of rows would take much longer than just using a where clause in a sql statement.