There are many more locked phones in drawers or acting as mere paperweights than people actually care to disclose.
Several years back we ran a poll to understand lifetime recycling habits. People aren't proud of dropping a phone and shattering the screen, but they are less proud of having thrown a phone into a drawer because they couldn't be bothered to run the obstacle course set up by their telco to keep them in check.
Phone right-to-repair should be EXPLICITLY INCLUSIVE of unlocking, otherwise it is only solving a part of the problem.