I’m personally going to use points on southwest for my backup flights, but I have some Delta credit that I’ve booked and rebooked with a few times that doesn’t expire until Dec 2023. No cancellation fees any time I cancel.

Also, I got an email from Southwest recently that said starting next year (in May I believe) that if you book a flight with points and don’t use it, and don’t cancel within 10 minutes of the scheduled departure that you will lose the points that you used to book that flight. I’m not sure if the taxes will be able to be used again as a credit or will also be forfeited.