I wish people would stop including the information as then it takes away the risk that they can't later claim that they didn't get the job because of their age, sex, martial status, etc.
They have some guidance on how to encourage equal opportunities in the job application process [0], the monitoring questions here [1] should be seen as things that should not be asked in a standard application process, nor included in a CV.
There's many attributes that we can't legally discriminate against when someone applies for a position [2]. We might be a little more aware of trying to ensure the process is fair and balanced, and it's certainly quite different from other parts of the UK and Europe.
[0] https://www.equalityni.org/ECNI/media/ECNI/Publications/Empl...
[1] https://www.equalityni.org/Employers-Service-Providers/Small...
[2] https://www.nibusinessinfo.co.uk/content/equality-law-and-ty...
*edit - fixed formatting of references