Talk to them-tell them how you feel.

I do not have a landline such
If is important they cannot get hold of me they leave a message if not is not that important
I do not worry about it.

If you can set individual ringtones set theirs to a silent tone. Explain what you have done so it's not to be aggresive. Explain you don't like that and will get to them when you feel okay to, or they can text, message etc ... ? ? Just gotta train em lol.

I text more.

I used to always leave people messages, but I quit doing it at work since they don't listen and just call back. I don't want to waste my time in telling them twice. However, if you call me and don't leave a message, I don't know that you called. I ignore my missed calls, but not my messages.

I don't listen to messages if you can't reach me leave a text.

I’m GenX. Messages are a waste of time. We are way passed those olden days...?

Younger people don't have the patience to listen to messages anymore. Text is great for simple short communication but not sufficient for many conversations.

After reading your comment further detailing exactly what you mean, it doesn't necessarily sound like your problem is aimed at millenials or GenZ, but the places in which you do business or the places that are trying to do business with you. At that point, it sounds like you should block the unfamiliar numbers that you -can- see, if any, and find a different bank if you can. My insurance agent has people my age and younger under her employ and they always leave a message when they call. Since you're not talking about family and friends doing this, i think it'll be tough to actually stop but I'd start by going down to the bank and having a chat with someone.

I'm not talking about family here, people. I'll get official calls from my bank's number with hangups. Sometimes I'll get constant calls from numbers I don't know and I'm blocked from my seeing them. I can't block a number I can't see. Professionals don't text me, they aren't allowed and I don't grant permission. So it's no message hangups or constant calling.
This is a thing. I've read about supervisors who have made a point of asking what their Millennial subordinates left on a vital message, because the client never received one. The supervisors hear, "So and so never answered," so the caller just hung up. They should be fired if I miss important information because they can't follow protocol. Their mobile has voicemail just like mine does. It's there for non-personal callers to state their business and leave messages. People I know personally will text me.

Oh the arguments I used to have with my mum over this, when I dared to switch off my mobile. You know, sensible times, like on planes, in meetings, or after 10pm when I wanted to get some sleep. Her standard routine had become:

1. Ring my personal mobile.
2. Ring my work mobile.
3. Ring my land line.
4. Ring my personal mobile again and leave a rant on the voicemail.

Her argument always being "What if there was an emergency? How would someone get hold of you?" Not that any of her calls were ever emergencies. She just felt important enough that others should feel obliged to drop everything if she wanted to speak to them.

This was a woman who grew up in an era when most homes didn't even have a wired telephone. Even in the earlier parts of her adulthood (and my childhood) she lived in a society where if you'd gone out shopping for the day, you were uncontactable until you got home. If people knew exactly where you were, then they might have a chance of finding the phone number and catching you there, but broadly speaking, if you went out for the day, you were completely off the radar.

Yet having got used to a society where she felt connected to everyone else 24/7, she really couldn't handle the idea that someone might want to temporarily break that connection, for a perfectly valid reason.

The only way to tackle it is to have that discussion. Even if it does turn into an argument. If people persist in their behaviours after you've asked them not to, then you're well within your rights to block their number.

Its the internet doing it and mobile phones.

I don't return calls that won't leave a message, even if It's a friend. If it is not importal for you, it's not important for me.

Change your number or block them. I don't call people back unless they leave me a message. If they don't leave a message I figured it's not that important and I'll call when I feel like it.

People are still using phones? I hate them, since they force you to stop what you're doing and talk to somebody when you don't want to. Just message people, and let them answer, or not.