Change Fees account for a respectable amount of income for the airlines. However these benefits seem to outweigh the more dire need to enticing passenger bookings. This large source of revenue has already been curtailed by American Airlines, United Airlines, Delta Airlines, and Southwest Airlines. Alaska Airlines joined the group today and is permanently dropping change fees effective immediately.
This move is centered at improving passenger traffic and flexibility as airlines struggle to move forward during the pandemic. A Change Fee typically ranges from $125 to $200 and provides over $1 billion dollars/yr in revenue to these airlines. The hope is to sacrifice a small amount a revenue relative to the potential gain by luring back consumers to fly.
There are specific terms and conditions as to how this change applies to international flights, reward programs, and types of tickets. You may have to buy a refundable ticket for this to apply. The link below has a table which summarizes the airlines policies but make sure to review your airlines policy regulary as they seem to be change frequently.