Everyone is making valid points for it being fairly obsolete, but if I may offer a counterpoint
BRRRRRRRRRRRRRRRRRRT
This is a hugely bad investment, yeah? Everything I've heard about the A-10 is that it was made for warfare 30+ years out of date. Too low and slow.
For what fighting 5th gen fighters? Fuck yes. But for their mission set? Close (to the soldiers on the fucking ground?) Air Support, invaluable. I never once heard or thought "I wish they'd get rid of those useless crappy airframes!!" Mostly cause the sound them screaming across the sky and of freedom coming from their nose was just too heartwarming. I'll never hear it again but I am glad to know they are doing their best to keep them relevant to the people that count most. The soldiers with boots on the ground.
Except they're dead against any adversary with remotely modern air defenses... or 5th, 4th, and likely 3rd Gen fighters if they're around. They're amazing at fighting targets that can't shoot back though.
Yeah, but every time they try to get rid of it, thousands of people come out of the woodworks to keep it in service.
Everyone is making valid points for it being fairly obsolete, but if I may offer a counterpoint
BRRRRRRRRRRRRRRRRRRT