I don't know if you've been to a bar recently. Lots of them stick IDs in a scanner. I handed over my passport to a hotel recently, they took it away and photocopied it.

I'd rather trust an organisation which stakes its business on being secure than handing over my ID to anyone.

I have never been 'carded' in a bar in my life. Maybe that's a US thing. Bars here are required to make sure you're old enough but if it's obvious they don't have to card anyone.

its definitely a US/CA thing.

The penalties of serving alcohol to under aged are high, potentially losing your license to sell alcohol. Regulators perform random checks with plants to verify proper protocols are followed.