The internal filesystem layout used by photos is not intended to be manually browsed, it is non-trivial and undocumented. I might be able to recover the original jpg files, but any metadata such as organisation structure, tags, albums is locked up in proprietary closed formats. They offer an export function which gets you the jpgs, but not much else.
> there is nothing stopping you from using an iPhone 3G released in 2008
Security for one. Apple and Google have both built an extremely complex phone OS that needs constant patching to even remain "reasonably secure".
> you can still buy standard Bluetooth headphones
My concern is longevity, simplicity and sound quality. I would not want to use bluetooth.