Which is why [in the UK] you do not need to declare spent convictions and it is illegal to ask for spent convictions. Apart from in limited proscribed public safety roles (IE teachers etc) that require a criminal records check but that doesn't apply to entry level fast food jobs.

Unspent convictions is another matter. If someone has an unspent conviction that can and should be asked about.

My job is one that requires a criminal records check in order to get my licence from the government and I can't have any convictions, if I get convicted of almost any crime I will lose my licence. My employees though aren't checked beyond asking about unspent convictions. I have hired people who have declared unspent convictions which didn't seem relevant to the role.

https://www.gov.uk/exoffenders-and-employment