Every shoe is different. I have had shoes that were still going strong with 1,000km on them, and shoes that started feeling flat and gave me ankle and knee aches at 400km.
I don’t have a set number to retire shoes at, it is more about how they feel. When running in the shoes starts feeling consistently strained or gives me aches, it’s time for them to go.
The kms go by faster, and the bigger number is more satisfying.