It all rather depends on whose airliners you are talking about. Under regimes where the Airline, Airworthiness Authority, and Air Accident Investigator are one and the same to all intents and purposes, ie the Government, then I wouldn't rely on them being "so safe". The reason for when they are "so safe" is that these institutions are separate and independent of each other. Thus an Authority can be found wanting and be criticised by the Air Accident Investigator for example.That is the catalyst for all the technical, training, and reporting initiatives mentioned by other members.
It is of course a contradiction of that happy state of affairs that Military Aviation is usually self regulated and self investigated. You might therefore wonder if military aircraft are "safe", ie are they airworthy? You would be right to do so.