I use MySudo sometimes for calls, and really dont use the phone for any mobile calls.
Is there a benifut to having calls sent over WiFi vs mobile for security?
Or better yet, which one is best to choose in the option of whether to use wifi unless unavailable vs mobile/ or WiFi if mobile unavailable?

a month later

I read from a Privacy Focused Cell Phone Provider, from which I don't remember the name right now, that if one wants to have as much Privacy as possible, to only use WiFi for Phone Calls, and as such not to use any Cellular Date at all, but just WiFi for everything.

    thor WiFi calling is not secure. It is not end-to-end encrypted and only raises the bar for interception.

    If you want to call somebody securely, use an end-to-end encrypted service like Signal.