is figuring out this sort of stuff an exercise of trying to reverse engineer the product, or is it much simpler than I make it out to be? whenever I want to try and fix something all the videos I see people just magically know which places shouldn’t be shorting, and magically know which capacitor is causing it

Most of the time there’s a cap after which there are diminishing returns. A $700 phone will probably last you a good 3-4 years, compared to a shitty year or two with a $300 one. However, a $1500 phone isn’t gonna be that much better and won’t last that much longer to be worth it.

For some other people this might differ, but whenever I have to interact with them, the Apple docs are absurdly bad. They read more as an autogenerated list from the API than something an actual human wrote trying to be useful. In general I agree, for most languages/packages the official docs are great