For me it's not arbitrary. An android device is a general purpose handheld touchscreen computer that happens to be used for music. That means a bunch of things to me:

1. "Touchscreen first" UX

2. Heavier than it needs to be

3. Worse battery life compared to a non-Android device

Using a touchscreen in the rain is impossible. Running out of battery sucks. Going for a run with a 240g brick is no fun, it'll pull your pants down to your knees and trip you.

Compare the specs:

    Hiby R1
    Dimensions: 86.9 x 60.6 x 14.5 mm
    Weight: 118g
    OS: HibyOS
    Battery: 19 hour play time
    Price: $159.00

    Hiby R4
    Dimensions: 129.6 x 68.3 x 18.5 mm
    Weight: 231g
    OS: Android 12
    Battery: 11 hour play time
    Price: $249

These are the things matter to me, in addition to the UX, sound quality, Bluetooth support, expandable / removable storage and sane file-based playlists.