Many libertarians have advocated for police reform (e.g., bodycams, no-knock raid ban, etc.), but not necessarily for "defunding" along the lines of what many on the left. Also, remind me how many libertarians are in charge of large cities with crime problems? The overall number of "anarcho-libertarians" is vanishingly small in comparison to woke leftist idiots who have been elected across the country and who have their fingers pulling the strings of many other institutions (education, media, NGOs, etc.) Sorry, your argument doesn't stand up to scrutiny. So yes, in the present day, it is one group that has driven the "defund the police" narrative, and that's the left. Fortunately, the pendulum has begun to swing in the other direction.