Russia has the biggest disparity between claimed kills and confirmed kills in history by an epic margin.
Unlike russia the US doesn't send prototypes into combat to sucker other countries into funding it's development.
Saw a YT video by some "totally unbiased just factually reporting definitely-not-a-russian" a few months ago saying that dozens of SU-57s were operating over Donbas daily, and that contrary to lying western reporting production was proceeding at numbers western manufacturers could only dream of.
Upwards of a 10-1 advantage in jet aircraft, Ukrainian air force still flying after 1,124 days of unrestricted warfare.