I remember when phones used to be good.
Telemarketers have been around for a long, long time (Wikipedia claim “…the practice of contacting potential customers by telephone originated in the late 19th century.”).
I personally recall a lot more telemarketing in the 90s, though I was a kid and just passed the phone to mom or dad. But that was also a time when caller ID was a luxury, and not everyone had answering machines.
It’s a pretty standard bandwidth/latency tradeoff in my view: email is high bandwidth (it’s in writing, you can re-read, etc.), whereas phone is low latency (several back-and-forth explanations can happen in seconds). Each has its place.
If social anxiety is a factor, that’s a perfectly valid, but separate, issue.