Genuine question - Have you actually flown a drone in a forested area? In sparse forests, IR cams will easily see through from top, but even in moderately dense forests, flying below canopy is a sure recipe for hitting and breaking a propeller. Even with the more experimental and expensive type drones, penetrating forests is still a work in progress and has severe range and speed limitations.
I have actually flown a dji Avata in a forest, in fact there are fpv class called cinewhoops designed to fly indoors and in tight spaces. With some training, a soldier can fly it under the canopy or over or even close to the ground. Even the IDF uses Avata for recon inside tunnels. But, fpvs are more of a killer component in the hunter-killer combo, as in a drone with thermal optic (even commercial ones) should be able to pick up some heat source through the canopy. Once identified, fpvs can be used for a closer investigation of the heat source or even to take them out if its a kamikaze or bomber fpv.
I agree with the battery, noise and the range part. That is definitely a limitation however, there are ways to increase range which is currently being utilized in Ukraine and Russia. For the noise there is a new type of propeller which does decrease the noise somewhat but, still a limitation. Range also depends on the position of the pilot with respect to the flying area, for ex if the pilot is on a higher altitude and flying at a lower altitude than the pilot's position with LOS the range (video and radio) would be to its max. Avata can do a range of max 3km+ to and fro doing speeds of about 100+kmph and under canopy where I am also under canopy, I get about 500-600m NLOS (this can be improved a bit with flying more skillfully), after that the videos cuts off but, can still be controlled blindly which is of no use and this is with normal dji goggles, and there are ways to increase the range by attaching extra after market antennas on the goggles. Military fpv pilots these days use a standalone 6ft antenna for a far greater range LOS/NLOS than ever before. There has been a huge spike in fpv tech due to the ukraine war. Now there are fpvs with thermal cameras which makes them all the more deadly. And it continues to grow at a very fast phase. I am scared there will come a day were jihadist will use these drones from a remote location in a city to cause mayhem on a crowded civilian place. Like flying/guided IEDs. And law enforcement will not be trained on how to handle such a situation.
Me being a civilian with only militaryish exp in the NCC can think at least 100 ways where and how fpvs could be used. It can basically be used as a guided and controlled rocket projectile but, with propellers. Hopefully army recognizes this and employs it which would definitely reduce the current types of casualties. But, I am asking for too much.