It's not. It's very fast, especially for gaming. Playing POE 2 with GPT2 or a recent wine version at max setting on 60+ FPS on those days. On a M3 MAX.
Really need the fan to maintain clocks while stressing the CPU and GPU. Still depending on the game the Air can still be pretty impressive, especially for native games.
I played horizon zero dawn on my M2 Air. It ran in 1080p and better than on my old PC on 720p (i5 4570, gtx 960). I had to plug it in and follow the wiki though. There's a regedit change to do for some cpu frequency thing, otherwise the games runs in slow motion - not slowly as in low framerate, the framerate is good, it's just time passing slowly.