Graphing Calculators are computers in every sense, it's hard to find one you can't at least program in a high level language like Basic or Python, and many accept assembly programs - even Texas Instruments models did, before their signing keys were brute forced.

Games consoles too almost invariably run third party code, although they tend not to be end user programmable - no different than an iPhone in that regard, really.

"Feature phones" - pre-smartphone phones with cameras and internet etc - usually had the ability to run Java Midlets without manufacturer blessing, even though you couldn't touch the OS. You could SSH into servers from those!

I think a big problem is that the distinction between "general purpose computer" and "end user programmable general purpose computer" is functionally meaningless when you can't write programs, which is most people. Instead they understand it in a functional context - what is this device for? How does it compare to how such devices usually work? The general purpose CPU inside is an implementation detail, and just because you think of an iPhone as a computer doesn't mean everyone does. They think of it as a "phone".