If all the music you want to listen to is available via streaming services than great, but I have a bunch of MP3s that aren't (things ripped from old CDs, music from my friends, music from anti-streaming artists).
With that needlessly arrogant attitude you might be surprised to learn that there's lots of music, new and particularly old, rare material, that has never been available via streaming. Or might disappear one day due to ending licensing deals. I'd estimate that about 20-30% of my collection isn't available via streaming and that includes pieces I do not want to miss.
I understand that this isn't as important to everyone, but as a music enthusiast I refuse to rent my music collection, which I intend to build and maintain for decades to come.
On the WCML, you have to pay ££ for WIFI unless you're in first class and even then it's patchy because the train doesn't always have a clear view for the satellite data.
> or you can just use 4G.
Down the WCML, you're lucky to get even 3G thanks to the combination of poor coverage from cell towers (not much call for them in rural landscapes, really) and the metallised glass they use on the trains.
(They did try per-carriage femtocells but they didn't help.)