Being in discomfort because my hands feel stiff and under tension is also annoying. It's not like I'm doing it for fun?

Are people actually doing this as a fun thing because there's nothing better to do?

Sorry to see the down votes you are getting. I am an inveterate knuckle-cracker, but I very much understand that a subset of people find it unpleasant and irritating to hear.

I have bad news for you about what happens your joints as you get older

I know right. Even makes me feel like the person doing it doesn't respect my personal space by making a sound whereas they could also just be quiet. Qualifies as misphonia probably; I feel like the strength of my reaction is unwarranted by something others seem to barely register or at least simply ignore.