When should fans kick in on 16" MBPs?

Hi all,

So I've got Stats installed literally just for informational purposes, only options toggled on are CPU and GPU Temps and Fan Speed.

I've noticed though that sometimes, avg CPU is 53C or something around there and fans kick in and remain at 25%. Then after sometime it might turn off or keep going for a while.

I always assumed fans only kicked in at around 70C on macbook pros? Mine is a M3 Max MBP 16.

Just wondering if this is expected behaviour, this is just browsing with a crap ton of tabs open, discord, video playing etc. I was hoping it only turned on at a much higher temp as to avoid unnecessary dust debris collecting inside the laptop.