> Honestly, this doesn't seem unreasonable to me. At some point, you have to cut off previous technologies because virtually everyone's moved to something better. You also can't buy tickets any more by snail mail with an enclosed check.

As long as the technologies you move to are equally freedom- and privacy-respecting. If I have to use a non-free spyware app to buy your tickets I'm not buying. Now, if you let me pay for and download a PKPASS that I can use on my fully-libre GrapheneOS smartphone then sure.