Airlines are like "instead of all those agents, we'll make a sort of assembly line manned by customers. Check in with one machine, drop your baggage off with another."

Then literally anything happens with the computer network requiring an elevated number of customers to need manual intervention, and suddenly you have an enormous immobile line while every single customer lines up before the two (2) remaining agents.

Corporations don't care about "efficiency" they just wanna fire people

I really believe this. We were told capitalist entities will act to minimize costs and maximize profit. But what corporations actually seek to do, for whatever reason, is minimize *labor* cost. They prefer to bear any other kind of cost. They will minimize labor costs even if it increases overall costs and/or hurts profits
All the airlines in Toronto now use this system where the machine prints you out a sticker tag you loop over your luggage handle, and then when you put it on the belt to be sorted a machine reads the tag. But it appears it only works if you put the tag on one way but not the other, chirality matters, or there's something the user can do wrong that makes the tag unscannable. So every airline has to inject a human into the process there to make sure you get the tag right, at the most awkward place
@mcc Our Ikea has introduced a dedicated checkout line that you can only use if you have their app, clearly in an effort to similarly reduce staffing.
Except, apparently, that is so unclear that they put a full size advertisement cardboard in front of it, blocking the lane, and have a human standing next to it, informing all would-be passers that this is the special lane, getting visual confirmation that the app is installed, and then temporarily moving the cardboard to let one customer pass.
@henryk Der inLichtenberg hat das, dazu aber auch eine normale Self-Checkout-Lane. Natürlich nicht ausgeschildert, auf meinen diesbezüglichen Hinweis meinte man nur "Ja, das ist doof, aber so vorgegeben, weil alle Filialen einheitlich sein sollen".