xDSL (x = e.g. A) has given us very fast Internet through the twisted pair copper wires once drawn to our houses for telephony. It has served us well. Almost anyone with a subscription can plug an xDSL modem into his phone socket and start surfing the Net. But all things must come to an end, and the end is now in sight for xDSL.
ITU, the gold standard standardization organization will soon ratify the G.Fast standard, which will give us gigabit/s through those humble wires that once carried voice only. That's technological development!
The question is as always: do we need it? A no-answer will appear laughable in a few years, so the safe bet is to answer yessss. We don't need it right away, because the services aren't there yet, but they will come. One thing leads to another. TV through the Internet is already there. G.Fast will enable the next generation TV through the Internet, and lots of stuff we haven't thought of yet.
I remember dial-up modems that could carry 2400 bits/s duplex, i.e. both ways. They were an improvement upon those carrying 600 bits/s one way and 1200 bits/s the other way. They operated in the frequency (on the twisted pair wires) that now carries voice. At that time faxing was all the rage. The last standard for fax modems gave them a speed of 28800 bits/s in 1994. But the Internet and its e-mail was about to break through and fax would no longer be needed. The faxing eighties were drawing to an end. By 2000-something dial-up Internet access was no longer acceptable.
In the eighties and nineties cable-TV had become popular and in the nineties they started offering Internet access and that access wasn't dial-up, but the real thing: constant Internet access.
ADSL was the technical solution for the phone companies. ADSL transported data in a different way than the eighties modems. It left the lower spectrum to voice and instead occupied the spectrum above. This use of the wires was strictly prohibited by the old phone companies, but that had to change. Thanks to competition the "cable-guys" gave phone subscribers proper Internet access.
ADSL was the given solution for households without cable. I remember what a luxury it was to read my e-mails without having to dial-up :-) Now Internet access is almost as important as electricity. What a wonderful innovating world!