"Large gender drop downs" is a canard, three is a large number for the purposes of their argument. It's not about gender dropdowns of any size other than exactly two as it's about strict enforcement of a rigid, patriarchal class hierarchy.

Accepting "the purpose of a thing is what it does" is important for these times. So is avoiding the epistemic traps of disingenuous actors.

Most internet forms that ask for gender have absolutely no reason to care about that information. Basically, biological sex should matter to healthcare professionals, and gender should matter to virtually nobody. So yes, "simply remove it" should be the answer to this most of the time.

I do not work on "internet forms" but medical research :)