and here's one missing phrase that has been bothering me for several years. The phrase "you're welcome" seems to have almost dropped out of existence. This particularly noticeable in TV and radio when moderators thank guests for their appearance or contribution.

"Thank you for that report, John."

"Thank you." ??? for what?....for thanking me?

VERY occasionally someone will say "thank you for having me.", but "you're welcome" is becoming rare. Why?