What do you mean you can’t call out on a Google Voice? You open the app and make the call.
If Google Voice has Siri integration which has been around for awhile, you can say “Call X using Google Voice” and it will call using GV and activate the phone Bluetooth protocol if you are connected to your car’s Bluetooth system.
I mean click on a phone number in my contacts app or on a web page and have the call go through Google Voice or dial in my default phone app and have the call go through Google Voice.
And it’s somehow harder to go to the Google Voice app and call especially when you can import your contacts?
What’s the fundamental difference between clicking on Contacts and making a call and clicking on the GV app?
If the GV app has been updated to take advantage of the latest APIs, calls to and from the GV app will show up in your call history along with the native dialer.
If you like GV, why use the native contacts app at all? Any app that adds to contacts will automaticallly be added to GV.
You entirely ignored the part about clicking on phone numbers in web pages. It's the same with any app. I should be able to use whichever contacts app I like, whether it is a unified contacts app, my LinkedIn contacts, my Facebook contacts, the maps application, etc. Any time I click a phone number to make a call, it should appear to come from my Google Voice number. Copying and pasting is horrible experience just to make a call.
Blame that on Google. If you use Chrome on iOS, they already give you a choice of which maps app to use and which mail client to use. There is no reason they couldn’t give you the choice of how to handle Tel links.
If Google wanted to since they already have all of the apps, you could completely stay in the Google ecosystem on iOS - Browser, mail client, google voice, etc.
You're grasping for excuses. There are security issues with running any app on your phone. A maps app could do nefarious things with your location. A browser app could do nefarious things with your browse history. That doesn't mean Apple blocks all third party apps.
If I trust a phone app enough to use its dialer, I should be able to route all calls through it. If I trust a maps app enough to use it manually, I should be able to set it to open for all address links. It really is that simple.