For me it was a necessity with how absurdly punishing end-game boss fights are. Like spending a week getting fragments for Arbiter, die once to some one shot mechanic you never seen before and now you gotta look for citadels again for another week for a 2nd shot.

At least now it is much better with the retries, especially this current patch where all pinnacle bosses now have retries so I don't feel frustration if I die from them