I’m pleased to report that a 20 year old iSight camera still works (in all its 640x480 glory) under macOS Sonoma.
All it takes is a Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter, a Thunderbolt 2 to FireWire 800 adapter, and a FireWire 800 to FireWire 400 adapter.

