There is a private company that picks up chips and tokens, returns them to the issuing casino, and brings the cash back.
They also bring back obsolete chips and tokens the issuing casino will not cash.

Those chips and tokens go in a "mutilated" box, and by gaming reg, are supposed to be destroyed.

Some small casino's do not have this service. They let them pile up and do a chip run on their own.
Some large casino's do not participate and will not accept foreign chips and tokens. MGM was one that did not at one time. Not sure of their policy at this time.