This makes 0 sense to me. There's literally no lock in with FB messenger. The second I get a video ad - that's it for FB video calls for me.
What do you mean? It's a messaging platform with built-in integration to the largest social network in the world. I couldn't possibly imagine a more textbook example of lock-in.
"Hey mum, I decided to call you because that video ad bullshit is bullshit".