you have a good point, many musicians hid behind the pedal, some of them are not as good as they sound, but proper placement and correct use of the pedal cover up a lot of flaws. But Inversions are simple and is a great tool to know fluently. Especially for those you play both organ and keys, some of those chords may sound great on keys but not as much on organ so that's where those inversions can also come into play. Knowing them can make the world of difference in your sound.