Routines check lists
We all take short cuts or get blase or distracted and we don't need sociology or psychology majors to do a study to tell us how and what pattern this is embraced. We already know this but need to ensure procedures minimise this human trait.
IF aircraft computers can talk to each terminal an automatic check list can be carried by on ground terminal computer BEFORE being given clearance to leave gate. Even so glitches will arise but it will reduce human oversight.
The cost? Ask the passengers or shareholders if $50 extra is worth it. It's executives trying to get bigger bonuses with too severe "savings" aided by accountants. All businesses should be run by experienced industry professionals and not transient ambitious execs.