I prefer the security of real wires and a phone system with independent power system for emergencies.
I used to work for AT&T back in 2001 when they rolled out their digital telephone campaign. In theory it was great. Phone, Internet and TV all on one cable. The suits loved it because the customer would get a three-in-one bill every month. In practice it sucked. I would end up explaining it to customers during the installation because the phone sales dweebs sold it with the, "it's cheaper than Pac Bell" pitch. That worked great, people love cheap. What they didn't tell customers was there was no system power
for their digital phone and that it ran off a big battery that had to be installed somewhere in their house. The battery was plugged into their electrical outlet, in other words the customer was paying for their phone to be powered up. Also, the customers didn't understand that when their TV cable is out their phone won't work.
So I'd get lots of questions from people,
It's the battery."
"Yeah to power your phone."
"But it's plugged into my outlet, am I paying for it on my electrical bill?"
"Pac Bell don't do that, the power comes down the copper pair of wires, right?"
Me: "Yep, 27 volts DC, simple as dirt, same set-up since 1876."
I would have a lot of interesting conversations with customers. My boss ended up hating me because I was educating customers on what a crappy system it was.
Customer: "You mean my phone is going to come over the TV cable?"
Customer: "But my cable TV goes out a couple times a month, will my phone go out too?"
Customer: "What if I have to call 911?"
Me: "Uhh.... got a cel phone?"
This was about the time I got out of Telecom.
My point is that I've never thought it was a good idea to put telephone on a TV cable. They didn't have system power at that time in San Jose, because they would have had to replace billions of dollars of plant, (cable) to make it work reliably enough. It's finicky. Especially on cable that is old and chewed. (Squirrel chew.) Why spend all that money? Like I said, the suits loved the idea. Three-in-one billing. So they rolled it out before plant was upgraded and before it was tested properly. So, they got sued by customers who couldn't get 911 on their AT&T digital phone in an emergency.
It was a mess.
Copper pair is much more robust and has far better uptime. The reliability is virtually 99.9 percent. If you're of a certain age, (like me) you remember your telephone was never out unless someone drove into a telephone pole and knocked it down. I for one lament the passing of Pac Bell and copper phone lines.