Wouldn't say so, personally! Beat Up has its uses, absolutely, but it's also far less consistent than Bite in my history.
Though the multi-hit move comes in nifty for breaking sashed ghosts and is arguably stronger than Bite at the start of a combat, using Maushold as a late-game cleaner will vastly prefer Bite to deal with Ghosts consistently, since it's generally assumed your team will be statused/knocked out on various levels, limiting Beat Up's power.
The consistency of a 90 BP Dark move (Technician boosted) allows Maushold to secure various K.O.s such as Gholdengo or Dragapult after a setup and/or Tera Dark, and the Flinch chance, while haxxy, is icing on the cake.
