Yes, seriously. It's your opinion and I have mine. I don't need your permission for that. But pretty much any store I frequent I have the wifi credentials saved to my phone. It's quite easy and I can talk and surf most everywhere I go in this fashion (though I wouldn't care to, really).
Also people need to stop stressing about always being connected 24/7. Enjoy the damn conversation and post ignorant selfies later.
Yeah, public wi-fi is a no go, especially if you're walking or on transit of some sort. I don't have Wi-Fi at work and find myself screwed when I'm on speakerphone and need to look something up for the call I'm on.
WiFi is not a replacement.
Using Voice and data at the same time is very common. When you're in a store, speaking to your spouse about a product, sending pictures back and forth about what you're supposed to pick up, etc. That is VERY common.
CDMA voice calling is on the way out. VoLTE is better.