headshots and therefore crits for amby were nerfed a long time ago
https://wiki.teamfortress.com/wiki/October_20,_2017_Patch
Spy
Ambassador
Players that are head-shot from across the map are expecting to see a Sniper in their death-cam, but they sometimes see (more often that we'd like) a Spy with a revolver
Goal: Reduce the effective combat range to something more reasonable and expected with the Spy
Changes:
Headshot damage is now subjected to distance falloff effects
Headshots beyond 1200 world units do normal (non-crit) damage