It can't be excluded. I remember a friend of mine overclocking his CPU (around 20 years ago!), and notificing that the maximum clock they could achieve, would d

It can't be excluded. I remember a friend of mine overclocking his CPU (around 20 years ago!), and notificing that the maximum clock they could achieve, would decrease over time. I guess that when put under thermal stress (which may be the case for some phone, for whatever reason) may actually have a measurable effect.