I have only ever needed my birth certficate once. When I got married. I was living in a foreign (but still EU-) country at the time; I have no idea if I would have needed it to marry in my own country. It’s possible my mom might have needed it when I was little, to get me into elementary school or something, no idea about that. It’s definitely not needed for a driver’s license or a house. That’s ridiculous.
I found out that the best way to make (certain) people stop asking it is to just be entirely honest for a change.
Don’t say “I’m fine, thanks. And you?” Launch into a depressing tirade about everything that sucks in your life and the world. Trust me, they’ll never ask again.
Heavenly peace.