Part of me feels that Rey holding the lightsabers of the two Skywalkers who helped shaped her to be the Jedi -
holding their legacy against the man who ruined their lives - is more symbolic and meaningful.
It is also symbolic of if Anakin (Skywalker saber) had stood by Mace (purple lightsaber) to reflect the lightning back at Palpatine. It’s about correcting the mistakes of the past.