Its all quite basic
Yes Life Boat drill is a pain in the A**, but it is done for two main reasons
One, its maritime law and the line/ship has a legal duty to perform it.
Two, if that ship goes down and in today society of suing everyone that a person can possibly sue, then if you did not attend and you happen to be on a ship that sinks and cant find your muster station and one of your party drowns since you did not turn up to the drill and find your muster station,,,then damage limitation for the insurers in your case.
But number one they do it because its the law, simple