Earlier quoted context omitted.
The concept of people leaving audio messages _with a reasonable expectation that someone will listen to them_ is (thankfully) dying out, at least among my social circles. You can leave a message if you want, I'm not going to listen to it. The only entities that make unexpected phone calls are scammers and bots.
I get spam calls but I never get spam voice mails. As such I never pick up unexpected calls but I do listen to messages. Might be a regional thing?
> I never get spam voice mails
You must not be in the United States then. Pretty much guaranteed every phone number in the US has received at least one “automobile extended warranty” voicemail.