The overarching issue is that this feature of the PS3 not only created cost in development/maintenance, but then negatively affected the core revenue-stream. So it was shut down, and Sony will never do this again.

Now we're at a point where there is no justification even for the cost of development/maintenance of such "open compute" features. Why even create a path for parts of your product to be "without rails" when there is no (legal) requirement for it and no significant commercial market, but just increased cost and complexity as well as security-risks.

I would like to see more devices being unlockable and provide the freedom to run "any code we want". But as there is no visible critical mass willing to pay for this, there is no market, and this means the current economic system doesn't support a company walking such a path.

So the only path I can see is to introduce an incentive for this into the system via a legal mandate, or change the system.