My current companion pass, earned in January 2022, runs through December 2023. I buy a ticket for myself, my wife is my companion (so most trips cost us just TSA fees for her travel) and then I redeem Rapid Rewards points for my daughter’s seat.
If you live in a big Southwest city as I do (they’re the largest carrier in Austin) and you have the time to take advantage of the offer, it’s a good one.