https://yarchive.net/bike/tire_talc.html

In the days before tubeless tires on cars, automotive tubes that were
not much thicker than the heavier bicycle tubes vulcanized into the
tire from the heat of the road and would rip when forcefully removed.
For this purpose, talcum was extensively used. Bicycles don't have
enough power not enough rolling resistance to generate vulcanizing
temperatures required to cause such adhesion so using talc has little
purpose. You'll notice that tubes contain talcum, and that is for the
purpose of preventing adhesion in the package of two absolutely clean
surfaces. You don't have that problem. In fact, adhesion of the tube
to the casing prevents rapid air escape in the event of a thorn
penetration.

Talcum, like tying and soldering, will last as much as 40 years after
the last need for it vanished. The last need for tying spokes
together at their crossings vanished with high wheeled bicycles that
threw the rider if a spoke broke and lashed about freely. Talcum in a
bicycle tire never had a reason, it has always been done in imitation
of automobiles, but even they don't use it anymore.

Jobst Brandt