It seems plausible to me that some people would have learned similar correlations between chat notifications vs ringtones.
First things first: Everyone hears your end of the conversation with a voice call. I absolutely hate that: My family would pick up pieces (by accident or not) and when my ex's mental illness was worse, he would listen. Period.
But there are also other things: I can flush the toilet. I don't have to do as many "formalities" and I don't have to stop everything I'm doing to have a conversation with someone.
I figure communication goes on a sliding scale of intrusiveness. Video is the most intrusive (I don't know why old sci-fi wanted this!)... and text the least.
I personally just prefer phone calls for any proper conversations, the odd "hello, how are you doing?" type messages are fine with text but if I actually want to talk to someone, phone calls every time.
People who prefer to create drama or interminable conversations can and do do so via any medium.
A reasonable theory would be that if your typing skills are good enough, the opposite is true.
Example, today on the train I texted a mate to see if he was about as we'd previously discussed meeting up today. I was going to get off the train at a particular stop if I was going to see him but otherwise would have carried on. I texted him and didn't get a reply until just before I was going to get off the train, which was about 40 minutes later. If I'd just given him a phone call, I'd have known immediately. It was all fine in the end but if I hadn't received his text before the first stop, I'd have continued on my way assuming he was busy. But because now the default method of communication is text messaging, I feel I can't make a phone call any more.
Voice calls are useful for things that need to be dealt with quickly but otherwise async communication is much more pleasant.
A voice call means they need my attention RIGHT NOW. (This is fine if it's during declared "office hours"). If the call is from someone I know, then it's likely they could have also messaged me or emailed me.
But if the call is from someone I don't know, it's either a scam or they're trying to sell me something. Some situation where they are more prepared than I am. But even then, text can be unambiguous in detail where I might fail to hear something in the call. And with text, I can generally take my time to reply when I choose to, can take the time to consider what to reply, etc. For better or worse, text omits a lot of "body language" aspects too.