Raspberry Pi cooling and heat sink
Heatsinks for Raspberry Pi are a popular accessory and are often recommended. Usually three pieces. One for the system-on-chip (SoC), one for the interface module and one for the voltage converter. Finally, equivalent building blocks in a full-size computer also have heat sinks.
Now, there is no reason to miss Raspberry Pi heat sink. On the one hand, in the ground state, it is not that powerful that the chips can get so hot that they are damaged. The chips are designed so that no problems occur in the narrowest case under full load.
Only if you overclock Raspberry Pi and operate it permanently at the edge of its performance, you could extend its lifespan with heatsinks. But who runs a Raspberry Pi in such a scenario, has quite different problems and should rather worry about a more powerful hardware.