I've interviewed people for roles as low-level C++/kernel programmers who did not know what hexadecimal was. Having a quick "What's 0x2A in decimal? Feel free to use paper & pen."[1] question can be a significant time-saver / direct people to more appropriate roles, if any.

[1] Starting to do math with non-base-10 numbers was already a pass, regardless of the number you reach, you'd normally use a computer for that. But it really isn't too hard to do in your head directly, for anyone who's dealt with binary data.

It's a choice to treat all candidates equally.

And intentionally excluding candidates is the whole point of designing an interview process, it's lazy to lift your arms up and declare that they're all biased.