Fired after 2.5 years due to "bad performance"

After my 1 year evaluation the verdict was 7/10. Pretty good with some decent air for improvement.

After my 2 year evaluation it was like 4/10. Pretty bad. Which I cant explain because personally I think I was at least 20-30% better compared to he year before. Even if im off by a factor of 10 - it would mean an improvement of 2-3%. Minimal but still an improvement.

Boss started micromanaging. No matter what I did it was not good enough. And half a year after my 2 year evaluation I was fired.

Is this normal? I never experienced anything like this. Normally if some is bad at theri job they get fired within the first year. But to fire someone after 2.5 years due to "bad performance" is new to me.