HN user
I have heard that this works legally, but that you have to be willing to take them to small claims court, and good luck getting them to actually pay when you win a judgement against them. (You'll have to hire someone else to actually collect the money from them, and that likely makes it not worth your time and/or money.)
So what happens when, for example, you're trying to get a home loan to buy a new house, and the loan officer is an older person who doesn't use texts? (This is something real that recently happened to me, and for which a phone and voicemail were indispensable.)
I find that while I can do what you suggest for friends and family, there are just enough situations where I can't do that, that I need to still have voicemail. Doctors offices that robocall to remind you of an appointment are another one. The occasional lawyer, or other professional who have a particular way of doing things. Getting rid of phone and/or voicemail just isn't a realistic option for a lot of people.
It's like a computer dialog box. Just as users don't read dialog boxes, phone users don't listen to the message at all. They just wait until the beep and start talking. I used to have a home phone that had voice mail boxes and we had a message that said, "To leave a message for husband, press 1, to leave a message for wife press 2." It had a default mailbox if the user didn't press anything. 95% of calls went to the default mailbox. People are idiots.
These exist for most phones and provider. However, having read the terms of service on them, they pretty much collect a bunch of data about you for marketing purposes, so it kind of defeats the point. They will, for example, collect the numbers of everyone who calls you. (They have to be able to do that in order to look up and block calls from known spammers.) No thanks.
There's an easy way to stop this. After it happens call the police and say you're getting harassing calls. They'll file a police report. You then call the phone company and tell them you've been getting harassing calls, have a police report, and would like to put a trace on your line. They'll give you a phone number to call. Whenever you get a debt collector calling you, you dial the number. After 3 or 4 calls, the police will contact the debt collector and tell them to stop calling you. They will.
Oh god, not just phone calls, but mail, too. And they make some weird connections. I once got a credit card offer that was addressed to me and a woman who's name I did not recognize. It took me a few minutes to realize that she and her husband ran the ISP I used. I was the business contact for my domain, but she was the technical contact since she was at the hosting company. Luckily my spouse is a very understanding person! She was like, "Why are you getting credit card offers with this other woman's name on them?"