@enigmatico I get that feel. Maintaining support for old technology forever is an unrealistic expectation, especially when it involves running costs and security costs. But I think it's well worthwhile maintaining bridges between old and new technology, even if it's technically cheating. The best tool for that is inexpensive "building block" SBCs like a Raspberry Pi. You can run something like Bitlbee to hook up anything that can access IRC to more "modern" messaging protocols like Discord or Facebook Messenger. You can run a text browser and access it from any computer with a terminal emulator and at minimum a serial port.

But mobile, yes, that's a tough one. I've tried going back to older phones a couple of times, going back to Symbian, to BB10. Changing encryption, horribly bloated modern webpages and older networks shutting down make it almost impossible. Within a few years, it will become an absolute requirement that a phone supports VoLTE to make calls on mobile networks at all. And it's not like people can run their own mobile providers.