How should I reply to demographic questions on job applications?

How should I reply to demographic questions on job applications? Can these only harm me or are companies genuinely using these questions to build a more diverse staff?

Some of these questions seem discriminatory and are now becoming a requirement in some applications I have submitted (age range, college graduation year, sexual orientation, gender, etc.) and are fairly commonplace across multiple companies I have been applying to.

Even the voluntary ones leave me concerned. For example, how do I respond to the question of having a current disability or a past history of one? The list of disabilities I have seen on these forms ranges anywhere from migraine headaches and depression to hearing impairment and missing limbs. How truthful should I be? I feel likes it’s a trap.

I haven’t even touched upon ethnic background questions yet! I’m multiracial and am not sure what to even put as an answer. Most options listed as a race and background category negate each other or do not allow for choosing more than one option.

Any advice, especially from recruiters and hiring managers, would be helpful!