Hah, I can share my perspective here as I am one of those guys who never ever want to take a call over the phone.
First of all, and most importantly: I am an introverted weirdo, just like you stated.
Most of technical people - are just like that.
Deal with it or get chatty over the phone call with that other guy who will then probably resell the service from us.
Another reason - very often people like you - who want to force talking details over phone - doesn't understand that sometimes a proper answer takes time to think about, might take a minute, might take few hours or even more. but it takes time.
Third reason, this is highly subjective but it is what it is: you will annoy me. and I get less annoyed by choosing the time when you will do so.
Another thing, phone calls are rude when unscheduled, and you cant imagine how many of my past agency clients did call me just to chat about their projects, dreams, future plans, and so on.
And people gets comfy with this, even if you scheduled your first introduction call, soon after you will get DMs like "hey can we jump in a quick call". No ffs, if I'm online, I'm working on something, stop being so rude and respect other people's time and work.
Personally, I think e-mails are best! They will:
1. force you to think before talk/write
2. gather together your questions, structure them
3. will let the recipient decide when to read/address your issue
for this reason, I never call myself if there is absolutely no other option.