Even though most of the satellites affected would be other Starlinks, I don't think the many entities with other spacecraft in sub 550km LEO would be particularly delighted to lose them (and the ability to safely relaunch for 5 years)

Satellites in higher orbits do a lot that can't be done in LEO and typically have much lower collision risk (though GEO is fairly crowded). There are plenty of plausible candidate technologies for cleaning up debris, just few practical demonstrations (and even tracking smaller pieces is work in progress)