I would like to build a music player / device for an older person, not tech savvy user.
I have the MP3s on my linux desktop/laptop, but not all the metadata and cover art.
I’ve worked with RPi before, jailbreaking iPhones and roku. So I have some limited experience with small devices.
I’m wondering if I could obtain some kind of old/used android phone, remove all the apps so the home screen is completely empty, transfer via USB or ssh/scp the MP3 files (and metadata + cover art), then have some kind of music player app which would be the only app on the phone/device.
Then shutdown any wifi or internet connectivity, but still allow bluetooth to pair with an external speaker.
Quick search for a product that satisfies your use case that is available in my region:
https://www.westerndigital.com/products/mp3-players/sandisk-clip-sport-plus?sku=SDMX28-016G-G46B
There’s bound to be a plethora of cheaper and more expensive alternatives. And probably a lot on the used market as well.