No, close air support does not mean being close to the ground. It means engaging targets in close proximity to friendly forces
> In military tactics, close air support (CAS) is defined as aerial warfare actions—often air-to-ground actions such as strafes or airstrikes—by military aircraft against hostile targets in close proximity to friendly forces
With guided munitions and better targeting pods, close air support has shifted to dropping precision munitions from further away to minimize the risk from short range air defenses.
The problem with precision munitions is that you cannot manufacture, transport and drop enough of them to achieve as much as you can with bullets. The country footing the bill is likely to be impoverished by them if used at any large scale. :/
You need to be close to the ground if using bullets.
As I point out in another comment, the cost of a laser guided bomb is $20K [1]. Less than the operational cost of flying the f-16 for one hour [2]. The idea that precision munitions are prohibitively expensive to use for close air support is a fantasy.
Lets say we have 6 targets and a 2 hour mission. Let us assume that the F-16 and A-10 both cost $20,000 per hour to fly. That would be $160,000 for the F-16. Lets assume the ammunition for the warthog costs $1 each. That would be $40,780 for the A-10.
Oh, and the F-35 costs about $40,000 per hour to fly. For that, the same mission costs $200,000.
> The idea that precision munitions are prohibitively expensive to use for close air support is a fantasy.
Unfortunately, the math does not favor those munitions.
> Regular rounds fired by the GAU 8 also known as PGU-14/B Armour Piercing Incendiary Depleted Uranium Rounds comes at a hefty price of 136.70 dollars a pop.
While those are pricy, the military does not fire those from the A-10 anymore:
> Armor-piercing incendiary rounds “go through soft targets very cleanly and don’t do much damage unless they hit a critical component,” said the former A-10 pilot. “The type of targets in Iraq and Afghanistan did not warrant using API.”
> In military tactics, close air support (CAS) is defined as aerial warfare actions—often air-to-ground actions such as strafes or airstrikes—by military aircraft against hostile targets in close proximity to friendly forces
https://en.m.wikipedia.org/wiki/Close_air_support
With guided munitions and better targeting pods, close air support has shifted to dropping precision munitions from further away to minimize the risk from short range air defenses.