I honestly don't get why console makers get a boner at the thought of disallowing third party software.
What do they gain out of this?
With proper security protocols you can sandbox your application well enough that hackers shouldn't be able to get to the OS.
And if they do find an exploit, the vendor can always force an OS upgrade, and prevent downgrades with hardware fuses, with new games requiring the latest OS.
It's not like console vendors aren't doing all this right now.
Tragedy of the commons. By making the barrier to entry high, it means that only significantly capitalized businesses with significant assets to wager and lose can actually publish anything. It means that there's (less) app spam, because not every couch publisher can type "ChatGPT, make me a game with the default Unity assets."
If you want a device that does everything buy it. I don't care if my Roku doesn't do something all arm devices can do even though it can. I didn't buy a PS4 to install Ubuntu I want to pop a game in.
I think that is right, but I also think that quality control is very important to console manufacturers, particularly Nintendo. You don't think about it so much because the consoles haven't changed that much in market position in years.
There is lore that bad quality software destroyed the 2600. Battles SEGA and Nintendo, SEGA and Sony, Sony and MSFT really depended a lot on the quality of titles and the users experience. So they tend to want to control the experience more then say Google or Apple do on the phone. You can have shitty apps on a phone, but its a much bigger problem for a console.
What do they gain out of this?
With proper security protocols you can sandbox your application well enough that hackers shouldn't be able to get to the OS.
And if they do find an exploit, the vendor can always force an OS upgrade, and prevent downgrades with hardware fuses, with new games requiring the latest OS.
It's not like console vendors aren't doing all this right now.