The IBM PC lineage of putting unrelated components together by yourself is an anomaly in the history of home computers, or computers in general. Selling computers as a whole, with set hardware and software, is what used to be the norm, and it worked well for everyone involved. We are to some extent returning to what things used to be.
It didn't work that well for everyone (except the established vendors), otherwise it wouldn't have taken the market by storm. Modularity is a good thing to have for innovation. If we're returning to "fixed sets", that probably signals the exploratory period is dying.
Anyway, "general computing" doesn't necessarily mean mixing and mashing hardware. But it definitely means executing arbitrary software with full control over installed hardware. The trend line here is definitely from "more" to "less" of "general computing". We've started with raw metal and hardware diagrams being included in the instruction manuals; then diagrams disappeared, CPUs gained abstraction layers - but it was still fine, computing-wise. But now we're in era of OSes and even CPUs limiting what users can do with them, and multiple parties owning various pieces of a computer, with nothing left to own for the user who actually buys the machine.
> Modularity is a good thing to have for innovation
Is it though? Apple has innovated a whole lot more with the non-modular Macs and iPads than any generic x86 vendor has managed in years and years.
Modularity means software has to be designed for the lowest common denominator. And that in turn means that there is nothing to gain by innovating in hardware, because the software won't support it anyway.
Somebody who controls every part of both hardware and software can innovate much more freely than you can in a modular market. x86 PCs have been stagnant for decades now.
The Apple II had slots and was thus highly hardware-customizable. The ability to add specialized hardware to a general-purpose machine gives it that much more flexibility, whether it's additional storage, data acquisition, additional network interfaces, machine controls, etc.
Sure we have things like Thunderbolt today, but there's a lot to be said for putting the specialized stuff inside the case where it isn't cluttering up the desk and nobody can just unplug it and pocket it.
It was extendable, but not modular. You couldn't just buy different parts and put them together into an Apple II. It was sold as a whole, that you could add a few bits to.
The IBM PC lineage of putting unrelated components together by yourself is an anomaly in the history of home computers, or computers in general. Selling computers as a whole, with set hardware and software, is what used to be the norm, and it worked well for everyone involved. We are to some extent returning to what things used to be.