Every 5 years or so, a different publication will write an in-depth story about how difficult they are to replace, because nothing works nearly as well, and the controllers go back to using paper every time a new system is trialed. I think I've even read about them in a cognitive psychology textbook at uni.
I have heard experienced pilots lamenting that we're still using voice on a scratchy radio, with garbled audio and people accidentally talking over other transmissions both being constant problems, for essentially all vital comms.
While I have no problem with keeping that as a fallback, there's zero reason why we shouldn't have, at least for airliners that have two pilots, a text-based communication system. We can still convert the text to speech in the cockpit to keep awareness the same, but we could play overlapping transmissions one after the other. And think of the other advantages. People wouldn't get callsigns wrong, could be alerted specially when their callsign was being talked to...
It's complicated because we will need to cooperate with all countries, but it's not like we don't have ICAO to work within.
However, approach phases are exactly the same periods when the pilots probably shouldn't be looking at their FMCs and texting. Voice communication is faster, and so is acknowledgement of voice commands, while allowing the pilots to concentrate on more critical controls. For example, in many airports it is possible to get departure clearances and such via text, but take-off clearance and taxi instructions will still be voice over radio.
In that system you can tell what is going on by looking at in a glance and works with no power. Sometimes simple is a great answer.
However, I can think of one reason the 'no power' argument fails. They do a lot by radio. That needs power. Also you would need to retrain everyone. Oh and you probably would get locked into one company that wants to control the whole software stack and sell tons of support.
When my home was built in 1999, I poured over all the home automation systems. I opted for conventional wiring. But I did wire every room (myself) with cat5 cable and RG6 coax, in a star configuration. It has served me very well, no problems at all.
I don't use the RG6 anymore, as my TV service comes over the intertoobs now. The cat5 isn't supposed to work with gigabit equipment, but it works fine. Wifi has improved by leaps and bounds, but I still rely on hardwired ethernet, as it is stupid reliable.
I think the best idea is to install conduit as the house is built, so that outdated wires can be replaced with newer wires by just tying the end of the old wire to the end of the new wire and pulling.
Just be sure to inspect the house as it is being built, because I think one user on HN wrote that conduit was required by law, but when he went to swap the wires, he couldn't pull them - he discovered there was only pipe in the visible terminations, not the whole route.
There is something to be said for knowing how to deal with critical systems when the automation breaks.
A few decades later, similar story, he came back to work part time, when desktop publishing was all the rage.
Welp, of course the computers went down.
So they fired up the old hot metal typesetting machines and he manually set all 100,000 words of that Newspaper by hand, and then they went to print using 19th century steam powered print lines.
Except, that story is total bullshit that I made up. Because "the computer went down" is something we can mitigate much easier than doing everything by hand.
Sometimes the old technology actually is objectively worse, inefficient, and obsolete. Like floppy disks, or manually having humans close the books at a bank.
the digital version would require 10+ endpoints with 1000x points of failure.