We can't use our old battery-swappable (physical keyboard, headphone jacks, etc) phones because the networks they run on, which also run just fine (UMTS, CDMA2000, CDMAone, GSM, etc) have been shut down.
Not many people did before those networks shut down, as far as I saw. You can get 3G phones with swappable battery and headphone jacks and physical keyboards too though, can't you?