Fun anecdote: I visited the Philippines in 2022. I flew Cebu Pacific Air for a few domestic flights, and they had just setup an abundance of these self-check-in kiosks at their airport check-ins. While prior visits to this particular terminal would see six to eight staff working check-in counters, this visit only had two: one assisting with the kiosks, and one checking baggage. Wait times were long, kiosks were confusing, and people were agitated, but we all got through.
I just returned from another trip now in 2025. Flew Cebu Pacific Air again for my domestic flights. This time the terminal had only three self-check-in kiosks, they were shoved up against a wall aside from the check-in counters, and nobody was using them. Everyone was waiting in line to deal with a human. (In the consideration of both sides of this human-vs-machine argument, perhaps the reason why kiosks didn't succeed in the Philippines is because human labor there is very cheap.)
Regardless, the moral of the story is that airline travel is agitating. Companies that try to nickel-and-dime passengers (even budget airlines like RyanAir) by removing mature, reliable, human & paper & analog components from that experience in place of new, untested, anxiety-inducing digital counterparts may discover that the total cost is not worth the savings.