The clearest example of the deficiencies of identity documents in the UK is the "Right to Work" process.

If you're an employer, you are legally required to check that anyone you hire has the right to work in the UK. The penalty for hiring an illegal immigrant - even accidentally - is a £60,000 fine. The guidance on how to perform a Right to Work check is 60 pages. A whole industry of third-party identity verification providers has sprung up, because the system is so complex that most employers don't feel able to do it themselves.

Ironically, performing a right to work check on a legal migrant with a work permit is trivially easy, because we've digitalised the visa system. They give you their Home Office share code, you type it in to a website, and the website shows you a photo of that person and clearly states whether or not that person has the right to work. We already have a really good digital ID service, but British nationals can't use it.

https://assets.publishing.service.gov.uk/media/6878ead80263c...

https://www.gov.uk/evisa/view-evisa-get-share-code-prove-imm...