Totally. The Spad earned total respect. I read something similar that specifically listed Skyraider-inspired characteristics as the template for the A-X RFP.
As I recall, strategically, the infantry air support was designed to be handled by helo gunships. Again, there was an overlap - the gunships had anti-armor capabilities (particularly by the mid-80s). And, given modern composition of forces (with infantry supporting armor and vice versa) there was no One Unifying Tactic. Supporting infantry (CAS) was part of the A-10s mission.
But, if you had A-10s and AH-1 Cobras and had an infantry engagement separate from an armor engagement, the idea was to send the A-10s to the armor and the AH-1s to the infantry. (Also made sense given which branch operated which asset.)
This kinda ignores the USMC assets. They are a thing unto themselves.
So, getting back to a "replacement" - I'm not sure the A-10 can be truly replaced. It is kinda the opposite of the F-4. The F-4 did a whole bunch of things well. The A-10 was basically the best in the business at what it did. Except....
... the Su-25 is awfully good, too. There's an argument that it is the A-10ski. And, interestingly, the Russians aren't replacing it with anything. They are still manufacturing them (I think). Kinda tells you how the Russians think the next war will play out, eh?
The loss of the A-10s reflects the larger strategic shift to the philosophy of first-strike, bomb them to the stone age (ironically), then commit troops once the enemy has been "softened."
"Everything old is new again."
Back in the early 2000's, the Army decided to Mothball the M2 and M60 in favor of M249 and Mk19. Boots on the ground quickly proved the M249 wasn't up to task as a replacement. Guess a bunch of egg-heads didn't understand a 5.56 doesn't compare with a .50 BMG. Anyway, the M2 was quickly pressed back into service. We had to suffer several years till the 240B made it out.