Sometimes people use that question rhetorically because it feels polite, viewing it as a small talk precursor to ease in to actually just saying what they want.

I don’t like when people use it as such, because it is insincere, poor consent practice, and low-key manipulative due to the foot in the door phenomenon .

There are tons of legitimate reasons to not be comfortable with the question. Don’t have time, bad headspace, don’t feel comfortable… If they can’t understand that, I try not to care what they think of me.