Most providers and I think clients prefer to txt.
For the provider, they are often responding from "wherever they are" which may be the gym, the grocery store, their day job, etc. and having that type of conversation may not be easy or possible.
There is also the fact that most people under 30/40 txt all day long, it's their default communication
Some providers say explicitly in their ad "no phone calls"
If talking is important to you, I would state that in a txt and see if your provider is willing to accommodate that