Microsoft, Sony and Nintendo take a cut too and you can't sideload.
The only thing that should matter is the device's raw computing power. The user should have the same level of control over code execution that the manufacturer has post-sale. That should apply to every single appliance and product on the market that uses a chip.
It's not.
> The only thing that should matter is the device's raw computing power.
It's not.
The software & hardware that comes together in general purpose mobile devices is non-trivially different from simple raw “computing” capabilities.
My smartwatch has a CPU that is far less powerful than my WiFi access point. But I absolutely expect to be able to install third-party apps on my smartwatch. And I can't care less about making my WiFi AP drive an external monitory displaying spreadsheets.
FWIW, gaming consoles are not used as general-purpose devices. PS3 was probably the only console that attempted that, and it was utilized by less than 2% of users.
For me, a great criterion for "general purpose" computers is this: "Do people use the device to work with spreadsheets?" Mobile phones certainly qualify.
I don't want to run random self-made apps on my watch, I want it to work reliably at all times. And that is done by using APIs and frameworks provided by the smartwatch manufacturer.
There are fully custom watch solutions where you can program everything from bare metal up yourself. Get one of those.
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As for the PS3 "general purpose" thing, it was 100% to get around EU tariffs. PCs were on a lower tariff than gaming consoles.
Both consoles run pretty much off the shelf PC hardware, iPhone has a custom chip.
There is no valid reason why I shouldn't be able to install, say, Firefox on either of them. The architecture is there and on the Xbox even the APIs are there.