A 2020-era iPhone has good default-setting software. That's good for learning about framing.
Beyond framing, though... The sensor is pretty meh; use an app like Halide to take fully-unprocessed raw shots (not still-Apple-processed Raw out of the camera app) to compare. The processing is good, with a caveat - it's good at producing a certain look, but there's limited ability to go beyond that with the default software.
Still, old iPhone + Halide will let you learn a decent bit about exposure and shutter speed and ISO. Not being able to control aperture is gonna be your biggest drawback in terms of learning about photography. But having a sensor that's a bit less forgiving than a Fuji one might be good for playing with - make the hard decisions about framing instead of just assuming everything will always be well-exposed. (I haven't used the X-half, but a considerably cheaper used X-whatever would be much better than a 2020 iPhone for non-computationally-processed shots).
Beyond framing, though... The sensor is pretty meh; use an app like Halide to take fully-unprocessed raw shots (not still-Apple-processed Raw out of the camera app) to compare. The processing is good, with a caveat - it's good at producing a certain look, but there's limited ability to go beyond that with the default software.
Still, old iPhone + Halide will let you learn a decent bit about exposure and shutter speed and ISO. Not being able to control aperture is gonna be your biggest drawback in terms of learning about photography. But having a sensor that's a bit less forgiving than a Fuji one might be good for playing with - make the hard decisions about framing instead of just assuming everything will always be well-exposed. (I haven't used the X-half, but a considerably cheaper used X-whatever would be much better than a 2020 iPhone for non-computationally-processed shots).