> it’s actually a bit of an oddity that computers had this brief moment of hackability. You can probably turn an old washing machine into a lathe

Yours is a wildly misleading analogy. The design of Washing Machines (WMs) contains no elements solely dedicated to preventing the off-label use of them, the analogy with phones would be a WM that comes surrounded by barbed wire, a moat and self-destruct explosives attached to the WM to brick it in case the owner tried to unscrew some screw or another. Then a technician with an unauthorized key for your home visits you whenever he wants and messes with the WM and its "defenses" at his pleasure.

There was no "brief moment of hackability" for WMs because they were always hackable to the max - as much as the basic usage design allowed. The WM manufacturers neither acknowledged nor prevented the conversion of WMs into lathes or any other artifact for that matter, that's up to the owner to decide. So yeah, make phones like WMs and stop crippling and messing with people's property.

Incidentally, the off-label use of drugs saves a lot of lives every year. Should we add poison to them to prevent that? Because that's what phone manufacturers are doing to the their phones under the merciless prodding of the OS suppliers.