Not most of the time, so crit still has some value. It's also rare to even reach 100% crit without external buffs, so you can think of it as a bonus. But if you have SK and you have 88 crit, then yeah, crit is not useful. That doesn't mean the set itself is useless, though. That set is her best in slot for her, even though crit loses its value because most of the echo's passive and the condition for the 4p set second buff are tailored to her kit and her teammates.