For probably over a decade, I've strongly thought the most important question you can ask somebody is "How are you?", but it was only when I thought to write about it recently did I realise that that depends heavily on what I consider to be "most important.", at least when it comes to other people. And for me, that's everybody's well-being. Regardless of whatever else is going, whether I get on with you or not, and so on, as long as you're some reasonable standard of "okay" at least (preferably better than "okay", of course), then I feel I can get on with the rest of the conversation or my own things and whatnot.
Why did I decide to write about this? Because I think "How are you?" is a question often overlooked. In British culture, especially, it's typically used as a greeting rather than a question - "Hi, how are you?" is something you generally say/hear when you meet somebody, and it often seems to throw others off-guard when I actually emphasise the actual question in that phrase. Because how you are is actually important to me. I imagine there's a general consensus that people feeling good (in the well-being sense) is a good thing (this time in the morality sense), and that more people feeling better is better for society overall in many, if not all, ways. And so gauging how you are in terms of your well-being helps me figure out what to do and in what priority. If there's something wrong and maybe I can help right that, then I definitely want to help. If all's relatively well (or I can't help with something in particular), then I'll carry on as is but that doesn't mean I think you're always fine and to never ask again (though me saying this doesn't mean I only care to hear how you are if I ask, especially if something's wrong - whether I can help or not, please feel free to talk to me about anything or everything).
One of the other main advantages of this question is that it's an open question that invites you to say as much or as little as you wish, regardless of things being "good" or "bad" :) This is the distinct difference between "Are you okay?" and "How are you?" Whilst both are effectively for gauging a person's well-being, the former is a binary "Yes/No" question, whereas the latter can be all degrees of informative. That said, I still ask "Are you okay?" on occasion, sometimes if I think the person I'm asking feels comfortable to follow up and elaborate on their answer as if I had asked them "How are you?", and other times when a 'quick' method seems appropriate, be it because we're in a public setting where maybe intimate details won't want to be disclosed or we're between places/events or whatnot.
Long story short, if I ever ask "How are you?", "Are you okay?", or questions to that effect, I'm not asking as a formality/pleasantry (incidentally, I get confused when others ask it as a formality/pleasantry); I'm asking because I'm genuinely interested. On the flip-side, I do know I ask it 'too much' for some people, and I do apologise if it annoys you as that's not my intention at all. Rather, there are times where I notice a familiar/relatable situation where that question probably could/should have been asked, and so I ask it - to be safe and find out there was nothing wrong and I worried unnecessarily, rather than sorry for not asking and finding out only when it's too late.
P.S. I realise me going for an "I/You" narrative might suggest I'm directing this post at some individual in particular, but that's not the case and never should be (unless I explicitly say otherwise); if I ever have something to say to somebody in particular, I will tell said person in particular directly (but hopefully as considerately/politely as possible!).