From what I've gathered, heat absolutely does[1] affect[2] it[3]:

Subsequently, in 1967, Black of Motorola experimentally derived a median time to failure (MTTF, i.e., operational lifetime) model for EM in Al interconnects, showing that the time to failure due to EM is inversely proportional to both the current density and the absolute temperature of the interconnect.

[1]: https://infinitalab.com/blog/ic-failure-analysis-defect-type...

[2]: https://resources.system-analysis.cadence.com/blog/msa2020-b...

[3]: https://www.mdpi.com/2079-9292/14/15/3151#sec3-electronics-1...

Thermal cycles, heat, current, all contribute to degradations and failures. It just so happens that cycling is the worst and everyone knows "it's the power cycles that kills computers". Doesn't mean at all that electronics can't be damaged countless other ways.