Also interesting is the notion of ‘Kolmogorov Complexity’ - what is the shortest programme that could produce a given output? Worst case for a truly random sequence would just be to copy it out, but a programme that outputs eg. a million digits of pi can actually be quite short. As can a programme that outputs a particular block cypher for an empty input. In general, it is very difficult to decide how long a programme is needed to produce a given output, and what the upper limit of compression could be.
Having had one of the old Windows phones with a keyboard dumped on me at an old workplace, can confirm it’s completely possible for a phone to have a keyboard and be a complete piece of shit.
A good phone with a good keyboard may have some use cases. If you do a lot of writing but not any more computing power or screen space than a phone has, plus you want to be doing that on the move, then yeah. For me, can shitpost on forums using my phone in my spare time, and dealing with on-call work issues - having multiple tabs of Jira and Slack open, for instance - just isn’t really practical on a small screen.
If your job is very email-centric, then yeah, sure. Blackberry were very good for just having the stuff you need - email, vpn, ‘corporate’ office documents - in a form that worked.