You can use a keyboard and mouse on recent iOS versions as well (and it works very comfortably on iPadOS). You can also connect an adapter to use a big screen.
I disagree with your argument that smartphones should be general-purpose computers. I don't think that having a smartphone be a general-purpose computer provides a significantly improved amount of control for 99.9% of the population.
I disagree with your argument that smartphones should be general-purpose computers. I don't think that having a smartphone be a general-purpose computer provides a significantly improved amount of control for 99.9% of the population.