This post isn't intended for the OP, who I suspect posted to "vent".
It shouldn't be a surprise. Change fees are listed on the carriers website. Change fees are listed in your confirmation email. Don't like the change fees. You have a day to cancel your reservation and get a full refund (some exceptions). Ticketed passengers are subject to the fees in effect when you bought your ticket.
Change fees vary. Southwest doesn't have any change fee. Airlines sell fully refundable fares $$$. You can buy
travel insurance.
Southwest doesn't always have the cheapest fares. People who want some flexibility should be willing to pay more for a fare which includes it.
Change fees can all but make our credit worthless. Revenue from unused tickets, and change fees, are some of the reasons why fares are reasonably low.
Book enough flights over the years and it's inevitable you'll have to change at least one. Work schedule changes. Family member gets sick. Pet gets sick....
Some people book their flights too early.
For the OP, if it may not be too late. I'd wait to cancel the tickets. Find out how much notice, if any, you need to give the airline before your ticket is worthless. There is a chance a major schedule change will give you the opportunity to get a full refund to your credit card. The new schedule doesn't suit my needs, I'm going to book a flight with a different airline.