Under ideal conditions, the fan should never turn on.
I agree, but this is a notebook so right off the bat the conditions are
far from ideal.
It is the computer case that is responsible for providing adequate cooling. Considering tower PC cases, with support for multiple large fans and lots of vents to create a nice "flow" of cool air channeling through the case, are
still challenged to keep the components inside cool, it is no wonder a notebook case starts out inadequate.
Notebook makers can pack PC performance into a notebook case, but they cannot pack in the cooling - not while meeting the demands of road warriors (the primary notebook consumer) who insist on light weight and super thin notebooks.
Also, PC cases allow for easy access so users can thoroughly clean the interiors of heat trapping dust. Notebooks, with their proprietary designs, do not!
At least not for the "normal" user.
For these reasons, IMO, there is no such thing as a good "gaming notebook" or "desktop replacement" - but that's for a different discussion.
For sure, if your fan is running more often and louder/faster than normal, you need to look at cleaning. Remove all the access panels, covers, battery, slide-in cards and drives to expose as much of the interior as possible then blast out the dust with compressed air, or a can of compressed dusting gas. Just be sure to hold the fans stationary while blasting (I use a wooden Popsicle/glue stick) so you don't over-spin and damage the bearings. And if using canned dusting gas, be sure to hold the can level to avoid spewing frozen liquid gas.
If using an air compressor (the only way to go, IMO) just be sure the compressor is fitted with a suitable in-line moisture and particulate filter and set the PSI to 80psi or less.