Termux is the answer to many problems:)

Hmm... if they're on Android there are apps in Fdroid or Play Store that let you download arbitrary files. Kind of annoying Firefox doesn't have that function

Since this is an article about an Android phone, I realise giving an iOS solution for this may not be that helpful. For anyone using iOS, the Apple Shortcuts app has an action "Get Contents of URL". You can use this to make a shortcut to save the contents of any URL similar to using wget. I often find this useful, and highly recommend the Shortcuts app in general. It's not perfect, but helps add missing functionality.

Been a while since I used Android regularly, but there will be a similar (easier) method for a shortcut to download the contents of a URL.