So how much annually do you spend on your hobbies, anyways, if you're going to declare getting a new phone every two years "fucking insanely financially irresponsible" :p Glass houses and all that, right?
I mean... what kind of hobby is owning the latest phone? Especially when the latest phone is barely an upgrade over the previous one.
People spend more on their daily coffee than they would upgrading their phone every two years. Significantly more.
Since you asked... Tools.
I buy more tools than I should - Wood working, electronic, and more general purpose. It's not always cost effective, but I generally pick a new project (ex - making my dining room table, installing solar panels, building my own dining room chairs, making my wedding ring, etc) and then buy a new tool for that project.
Am I saving money vs just buying a decent premade thing? Usually not really (although sometimes!). But I get to learn, work with my hands, and expand capabilities, and feel nice having made a thing.
I can get a lot of tools (or a couple very nice tools) for the amount you'd spend on a new iphone.
Since we're having the conversation - I'll make a value judgement. I think more folks would be happier with the tools than a new iphone, and I think buying one every 2 years is a perfect example of "keeping up with the jones" style behavior - compulsive consumerism that's not improving happiness (With an understanding that there are exceptions - ex: if you develop mobile applications, I'll accept that a new iphone is essentially a new tool).