Yeah, Breaker isn't relevant anymore in today's meta. Even MST would be better because you don't have to use your normal summon and it's a quick spell.
breaker is for one in a thousand times that you were top decking against your opponents and need a beatstick to finish it. Better yet against a top deck drowning mirror force.
Also, this Skill does not require empty field or putting any summon restriction, so the Breaker can also be used as tribute or Fusion/Synchro/Xyz Material if you want to.
I also hope that they will update this skill again. Breaker is just useless in the meta. And Mirror Force isn't that good either. Pot of Greed, Graceful Charity, Giant Trunade, The Forceful Sentry or Confiscation would be a nice replacement. It would still be an unpredictable gimmick skill but it would at least be somehow useful.