In a modern IADS the higher you go the more likely you are to get swatted by a double digit SAM system. Small arms and MANPADS are lethal, but you have a better chance than trying to doge an SA-15 with an A-10.
Modern attack helo’s (we’ll go whiskey cobra’s forward) were developed to be a maneuver element versus a CAS platform, and big army peer conflict, doctrinally should be employed as such. There are very few platforms that can hide itself in terrain like and infantryman almost, fire off 8-16 ATGM’s in a matter of minutes, and redeploy tens of kilometers in a matter of minutes to do it again. Pointing an air cav battlation at an enemy motor rifle battalion and saying “kill that” is what they were designed to do. We have used them and view them as some kind of CAS or “flying artillery” due to how they have been used for the last 20 years, but that was actually using them out of their intended roll.
I have some thoughts on their employment in the COIN environment I’ll come back and add later. The short version, we in the west frequently equate a lack of technical sophistication (lack of MANPAD’s, etc) with a lack of tactical sophistication and intelligence. We have made that mistake throughout our military history, and it has cost us.