Interconnect materials commonly used are soft metals.
Al, Au, Cu. They are ductile. You can stretch or bunch
them with tension or pressure and they stay deformed.
So with current you have a different sort of force but
force, its drag energy left in the medium (I^2*R*t) does
work and moves atoms.
Consider these metals as, rather, a viscous fluid.
Temperature softens them (as it does everything, but
low melting point kind of -is- the point for sputter dep
(we used to run moly in one fab and tungsten in another
but both went on by CVD - both refractory metals and
no hint of electromigration).
Butter spreads way different cold, than warm.