Are you implying that the silicon somehow has a shorter lifetime due to the presence of an interposer layer? Or is this a way of saying you think cpus are going to become more powerful at a faster rate?
Before ryzen 3000 chiplets, CPU were everlasting, with failure rate of essentially 0 percent. AMD Ryzen 3000 chiplet failure rate was at least 5% first year and they keep degrading at astonishing speed.
Like 90% of mid to high end GPUs from AMD and nvidia produced before 2016 already dead, soon you will have to thoughtfully test CPUs to understand if its condition is still acceptable.
You can buy 15 years old cpu (which is 4 core 64 bit btw) and expect it to work like new.