This lame excuse to give out my phone number

When working with Microsoft support in an online chat, they have this lame excuse for me to divulge my phone number to them. It’s not new. It’s not just them. I have heard this before from many support reps.

“Just in case we get disconnected give me your phone number.”

What? I am doing an online text chat. You are not going to call me back. We both know that.