Agreed.I have been in electronic repair for over 50 years & I can 100% confirm that heat is the #1 reason for failures of electronic devices so anytime you can remove heat, the longer electronic devices in general will last. The biggest issue is typically with the component electrolytic capacitors as they hate heat & will fail much quicker in hot environment.
Modern receivers now are a combination of computer type microprocessors which generate heat combined with high power many channel amplifiers which can generate high temperatures when run at high volume for long periods on time with many receivers not really designed for all this heat generation so fan(s) are a very good choice to remove this heat. If your receiver is placed in a cabinet with glass doors on the front and/or a backing on the back of it, this can really restrict air flow to the receiver
which will create additional heat issues.
Rog
Before I packed up all my audio gear and moved it out of my audio cabinet into a different room, I rebuilt the cabinet years ago. On the back I cut holes for two 120 mm pc fans up top/back. In the bottom where the AVR resided, I always had a 240mm fan pulling the hot air out and blowing up through the back of the cabinet to the exhaust fans. None of the shelving extended to the cabinet back, allowing air circulation.
Now my two AVR's are free standing in the open but I keep the 240 mm fan on top pulling the hot air out. The fan is actually powered from one of my pc's.
Not sure what temperature the AVR's fan is set to come on, there's no mention of it all in the manual or specs.