I hate clicking the right stick so I never used dash in battle. I hope there's a button reassignment option I'm missing. It doesn't seem to have much utility unless youre a healer class needing to revive someone though ?
It's useful on bigger enemies if you want to shift positions too imo. Like starting on a side attack and moving to the back. Some enemies also back away from you when using attacks, so I found it useful to close the gap.