It's incredible it's all tracked in the first place and AFAIK there's never been a collision.

( Undulating Tentacles of Love getting fun down to acceptable levels, Mon 11 Nov 2024, 18:22, archived)

the ISS has to use its thrusters every now and again to avoid debris
i think there have been a few collisions and china blew one of its satelites up a little while ago causing a load more debris. it's definitely a concern.
( MiseryCunt why is my arse getting further away, Mon 11 Nov 2024, 18:39, archived)