Phone hardware's been growing up considerably faster than PC hardware over the last decade-plus, I think, but you're right that planned obsolescence exists and there's a tradeoff.
For me, these are professional tools, and reliability therefore outweighs just about everything else in my consideration of what to use. Tools that don't reliably help me complete the task at hand are the wrong tools, no matter what their other virtues, and nothing else I've tried has been more reliable in that sense than Apple hardware - granted, I haven't had as good a time with the Touch Bar-era laptops, but even they have still been head and shoulders over any past or present Windows laptop I've tried, and I'm not even going to talk about my experience with Linux on laptops because I have enough problems today without attracting a crowd of angry partisans. And from what I hear about the M1 laptops, Apple seem to have gotten their act together, in any case.
Outside work, I still need the appliances I use in daily life to be reliable. Apple's phones aren't up to the standard I prefer, but they come closer to that than anything else I've tried, so they're what I prefer in that regard too. I would like it if they seemed likely to ever again make a phone that's comfortably sized for my hands, but nobody else does either, so that's life, I guess. It's a lot of why I learned how to repair my SEs and where to get parts for them. When it's no longer tenable for whatever reason to keep using them, I'll figure out what to do next. Probably that will be a newer iPhone, because I don't think it's likely anyone else will come along to compete on the combination of compatibility, reliability, and active concern for privacy that matters most to me. I think it would be great if someone did, though.
In any case, as I think we've both said in this conversation, there are tradeoffs, and these are mine. I generally assume that other people who talk here about using an iPhone have made that decision after a process of consideration not wholly dissimilar to mine, and that anyone regularly on Hacker News probably has a good sense of alternatives given how they're regularly discussed here.