Nah, Alcaraz cost nothing and actually played quite a bit.
Niasse is in a class of his own in terms of being spectacularly bad. His highlights at Everton included running around in a circle when presented to the crowd, crippling Deulofeu and having a highlights video in one game that went perfectly in sync with the Keystone Cops music.
Alcaraz did cost us the Europa League though, so I think he's worse