This should be illegal, and anyone caught doing it fined twice the total cost of amortized ownership per each device owner over the total duration of ownership in addition to completely refunding every customer.
Throw in jail time for decision makers. Lets make markets honest with real incentives.
And/or abolish the DMCA "anti-circumvention" laws, which makes it a crime to pick (digital) locks that you own, or discuss how one might do so.
It's still a problem if manufacturers force ExploitationOS on the device I bought, but it's not-as-bad when everyone can collaborate to disable the exploitation-parts.
Why? There is a perfectly cromulent license, sitting right there https://www.gnu.org/licenses/gpl-3.0.en.html
It was even explicitly designed to prevent "tivoization." https://www.gnu.org/philosophy/tivoization.en.html
One just has to use it to prevent their software from being locked away from the end user
This isn't just about hardening devices against the owner, some devices by the nature of what they're doing have to go in places where their physical security can't be guaranteed, secure boot means that we can put those devices there and not worry about some kid with a USB stick coming by and either wholesale replacing the operating system with something else or injecting a botnet client into the running system.
For a start, stop buying those products: vote with your wallet.
Do you own a phone that's easily rooted? Who else does?
What about your WiFi routers? Internet modem? AirTags? Smart home appliances?